Servo driver control system based on DMX512 protocol and control method thereof

Abstract

The application discloses a servo driver control system based on a DMX512 protocol and a control method thereof; the system comprises a DMX512 signal input module, an RS485 transceiving module, a main control module, an output driving module, a servo driver and a servo motor. After a DMX512 differential signal is converted into a serial port signal by the RS485 transceiver, the signal is subjected to cross-domain processing by the main control module; a plurality of DMX channels are combined and reconstructed into high-resolution motion instructions and multi-dimensional servo parameters by a parameter mapping unit; a safety protection unit performs ramp limiting and smoothing processing on instructions with sudden changes in DMX channel values, and forcibly executes stop and interlocking arbitration when communication timeout or hardware emergency stop / limitation triggering occurs; and the processed signal is sent into the servo driver through an isolation driving module. The application solves the interface, resolution and safety logic conflicts between the DMX512 light protocol and industrial servo control, and is suitable for stage machinery, exhibition display and non-standard automation scenes.

Description

Technical Field

[0001] This invention relates to the fields of industrial automation control, servo drive control, lighting control protocol conversion, and embedded control technology, particularly a servo drive control system and control method based on the DMX512 protocol. Background Technology

[0002] DMX512 is a digital control protocol widely used in stage lighting, landscape lighting, performance equipment, and special effects control. It typically uses an RS485 differential bus for transmission and features simple wiring, strong anti-interference capabilities, and convenient channel expansion. A DMX512 control system can output multiple channels of data from a control console, with each channel typically corresponding to brightness, speed, position, or effect parameters ranging from 0 to 255.

[0003] Existing servo drives are typically designed for industrial motion control applications. Common control methods include pulse plus direction control, CW / CCW dual-pulse control, analog speed control, PWM control, and bus communication control. Taking Huichuan servo drives as an example, their common applications can achieve position or speed control through external pulse commands, direction signals, enable signals, and related I / O signals.

[0004] In stage machinery, lighting linkage devices, exhibition displays, art installations, movable landscapes, immersive spaces, and non-standard automated equipment, there is a need to use a DMX512 console for unified control of lighting, mechanical movements, and special effects equipment. However, DMX512 output signals cannot directly drive conventional servo drives; there are significant differences between the two in terms of protocol, electrical interface, control parameters, and safety logic.

[0005] Resolution and dimensionality mismatch: The DMX512 single channel has only 8-bit (0-255) resolution, which cannot meet the high-precision motion requirements of servo, and the single channel cannot express the multi-dimensional parameters required by the servo.

[0006] Command time domain characteristic conflict: DMX512 follower operation is prone to command abrupt change (step), which can lead to mechanical shock when directly converted into servo pulse;

[0007] Safety logic inversion: The DMX512 protocol usually maintains the last state when communication is interrupted (to ensure that the light does not go out), but this is an out-of-control state in mechanical control, which can easily lead to safety accidents.

[0008] Therefore, it is necessary to propose a conversion scheme to solve the aforementioned cross-border control problem. Summary of the Invention

[0009] This invention aims to solve the problem that existing DMX512 control systems cannot directly control industrial servo drives. It proposes a control system that combines protocol conversion, signal shaping, control mapping, and safety protection. Specifically, it addresses the mismatch between the low resolution of the single-channel DMX512 and the high precision parameters of the multi-dimensional servo, the mechanical shock caused by sudden command changes, and the conflict between lighting protocol holding logic and mechanical safety logic.

[0010] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0011] In a first aspect, the present invention provides a servo driver control system based on the DMX512 protocol, comprising:

[0012] The signal input and conversion module is used to receive DMX512 differential signals and convert them into serial logic level signals;

[0013] The main control module, connected to the signal input and conversion module, internally incorporates cross-domain adaptation logic from lighting protocols to motion control. The main control module includes:

[0014] The cross-domain parameter reconstruction unit is used to parse DMX512 data frames, reconstruct low-resolution single-channel light attribute data into high-resolution motion commands through multi-channel cascade combination, and reconstruct discrete channels into multi-dimensional servo control parameters according to functional domains. The multi-dimensional servo control parameters include soft enable logic.

[0015] The kinematic adaptation and smoothing unit, connected to the cross-domain parameter reconstruction unit, is used to intercept step target commands generated by the DMX512 protocol without a handshake mechanism, and to perform incremental limiting and smooth transition processing on high-resolution motion commands based on mechanical inertial constraints.

[0016] The cross-border safety interlock unit is used to overturn the default hold logic of the lighting protocol and force a shutdown when the DMX512 communication times out, and to forcibly disable the soft enable logic when the hardware safety signal is triggered.

[0017] The signal output and isolation drive module is connected to the main control module and is used to output the control signal after smoothing and interlocking arbitration by electrical isolation and power enhancement.

[0018] Servo drivers and motor modules receive control signals to execute mechanical movements.

[0019] Furthermore, the specific reconstruction logic of the cross-domain parameter reconstruction unit includes:

[0020] Extract the continuous first DMX channel data as the high byte and the second DMX channel data as the low byte, and combine them to generate a 16-bit or 32-bit high-resolution motion command.

[0021] Extract the data from the third DMX channel and compare it with a preset direction threshold to generate direction logic. Extract the data from the fourth DMX channel and compare it with a preset enable threshold to generate soft enable logic.

[0022] Furthermore, the kinematic adaptation and smoothing unit performs the following smoothing algorithm:

[0023] Within the current control cycle, calculate the frequency difference between the target pulse frequency and the current actual output pulse frequency;

[0024] Determine whether the absolute value of the frequency difference is greater than the preset maximum frequency increment per single cycle;

[0025] If it is greater than, the current actual output pulse frequency plus the maximum frequency increment is used as the final output frequency for this cycle; if it is less than or equal to, the target pulse frequency is used as the final output frequency for this cycle.

[0026] Update the register value of the pulse generator based on the final output frequency.

[0027] Furthermore, the specific interlocking logic of the cross-boundary safety interlocking unit includes:

[0028] The interval time of the Break signal in the DMX512 data frame is monitored in real time. If it exceeds the preset communication timeout threshold, the communication is determined to be lost, and the servo enable signal is actively set to an invalid level to overturn the default hold state of the DMX protocol.

[0029] The hardware emergency stop input signal and limit switch signal have the highest priority. When either hardware signal is in a valid trigger state, the current value of the soft enable logic is unconditionally overridden, and the pulse output channel is forcibly locked.

[0030] Furthermore, the signal output and isolation drive module includes a high-speed digital isolator and a differential line driver:

[0031] The single-ended pulse output pin and direction pin of the main control module are connected to the input of the high-speed digital isolator, and then connected to the differential line driver after isolation;

[0032] The differential line driver converts a single-ended signal into two inverted differential pulse signals (A / B) and a differential direction signal conforming to the RS422 standard, which are then connected to the differential command input port of the servo driver.

[0033] Furthermore, the signal access and conversion module includes an RS485 transceiver with magnetic or capacitive isolation and peripheral protection circuitry:

[0034] The RS485 transceiver connects to the UART peripheral of the main control module via a DMA ring buffer to identify the Break signal and start code of the DMX512 protocol.

[0035] The peripheral protection circuit includes a 120Ω terminating resistor located at the end of the bus, surge electrostatic protection devices, and a common-mode inductor.

[0036] Furthermore, the multi-dimensional servo control parameters include operating mode selection parameters. The main control module switches between output pulse plus direction control signal, CW / CCW dual pulse control signal or PWM duty cycle control signal according to the value of the mode selection channel in the DMX channel.

[0037] Secondly, the present invention provides a servo driver control method based on the DMX512 protocol, comprising:

[0038] Receives DMX512 differential signals and converts them into serial logic level signals;

[0039] The DMX512 data frame is parsed, and the low-resolution single-channel light attribute data is reconstructed into high-resolution motion commands through multi-channel cascading combination. The discrete channels are also reconstructed into multi-dimensional servo control parameters containing soft-enable logic according to functional domains.

[0040] Intercepting step-type target commands generated by the DMX512 protocol without a handshake mechanism, and performing incremental limiting and smooth transition processing on high-resolution motion commands based on mechanical inertia constraints;

[0041] When the DMX512 communication times out, the default hold logic of the lighting protocol is overturned and a shutdown is forced, and the soft enable logic is forcibly disabled when the hardware safety signal is triggered.

[0042] Based on the control parameters after smoothing and interlock arbitration, the output pulse, direction or PWM control signal is used to control the operation of the servo motor after isolation and differential drive adaptation.

[0043] Furthermore, the steps for incrementally limiting and smoothly transitioning commands based on mechanical inertia constraints specifically include:

[0044] Calculate the difference between the target pulse frequency of the current cycle and the actual output pulse frequency of the previous cycle;

[0045] Determine whether the absolute value of the difference is greater than the preset maximum frequency increment per single cycle;

[0046] If yes, then the actual output pulse frequency of the previous cycle plus the maximum frequency increment is used as the final output frequency of this cycle; if no, then the target pulse frequency is used as the final output frequency of this cycle.

[0047] Furthermore, the specific steps for forcibly disabling the soft enable logic include:

[0048] Real-time monitoring of the status of the hardware emergency stop input port and limit switch port;

[0049] When a valid level of a hardware emergency stop or limit signal is detected, the parsing result of the enable channel in the DMX channel data is skipped, the servo enable control variable is directly set to an invalid state, and the pulse output channel is simultaneously turned off.

[0050] The beneficial effects of this invention are: it realizes the protocol conversion between the DMX512 control system and the industrial servo drive, enabling the lighting control console to indirectly control the movement of the servo motor;

[0051] By combining multiple DMX channels into high-resolution control parameters, the limitation of single-channel 8-bit resolution is overcome, and the servo control accuracy is improved.

[0052] By limiting the ramp and acceleration of the sudden change command, the mechanical shock caused by the step operation of the DMX push rod is avoided, thus improving the smoothness of the action and the safety of operation.

[0053] It features communication timeout shutdown and hardware / software safety interlock logic, correcting the safety risks of DMX protocol hold logic in mechanical control and ensuring system security;

[0054] By employing isolation and differential drive adaptation, the system's anti-interference capability in industrial or stage environments is improved. Attached Figure Description

[0055] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 This is a system architecture diagram of the present invention;

[0057] Figure 2 This is a flowchart of the process of the present invention. Detailed Implementation

[0058] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0059] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0060] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0061] Reference Figures 1-2 As one embodiment of the present invention, this embodiment provides a servo drive control system based on the DMX512 protocol, comprising:

[0062] The signal input and conversion module is used to receive DMX512 differential signals and convert them into serial logic level signals;

[0063] This module is responsible for receiving DMX512 differential signals from the stage lighting control console and performing electrical conversion and protection.

[0064] like Figure 1 As shown, the DMX512 input module includes a standard DMX512 interface and a 120Ω terminating resistor at the end of the bus to reduce signal reflection. To cope with the complex electromagnetic environment of the stage and long-distance cabling, the input is also equipped with surge protection devices (such as TVS diodes) and common-mode inductors.

[0065] The RS485 transceiver module uses an RS485 transceiver chip with magnetic or capacitive isolation (such as an isolated transceiver) to convert differential signals to UART level signals from the microcontroller. Its receiver connects to the A / B lines of the DMX512 bus, and its output connects to the UART RX pin of the main control module. The main control module receives data through a DMA ring buffer combined with serial port idle interrupts, and uses a timer to precisely detect the Break signal and start code, completing frame parsing and abnormal frame removal.

[0066] The main control module, connected to the signal input and conversion module, internally incorporates cross-domain adaptation logic from lighting protocols to motion control. The main control module includes:

[0067] The cross-domain parameter reconstruction unit is used to parse DMX512 data frames, reconstruct low-resolution single-channel light attribute data into high-resolution motion commands through multi-channel cascade combination, and reconstruct discrete channels into multi-dimensional servo control parameters according to functional domains. The multi-dimensional servo control parameters include soft enable logic.

[0068] The kinematic adaptation and smoothing unit, connected to the cross-domain parameter reconstruction unit, is used to intercept step target commands generated by the DMX512 protocol without a handshake mechanism, and to perform incremental limiting and smooth transition processing on high-resolution motion commands based on mechanical inertial constraints.

[0069] The cross-border safety interlock unit is used to overturn the default hold logic of the lighting protocol and force a shutdown when the DMX512 communication times out, and to forcibly disable the soft enable logic when the hardware safety signal is triggered.

[0070] The main control module (using an STM32 series microcontroller in this embodiment) is the core of the system. It contains cross-domain adaptation logic from lighting protocols to motion control, and mainly includes the following units:

[0071] The signal output and isolation drive module is connected to the main control module and is used to output the control signal after smoothing and interlocking arbitration by electrical isolation and power enhancement.

[0072] Servo drivers and motor modules receive control signals to execute mechanical movements.

[0073] The main control module (using an STM32 series microcontroller in this embodiment) is the core of the system. It contains cross-domain adaptation logic from lighting protocols to motion control, and mainly includes the following units:

[0074] 1. Cross-domain parameter reconstruction unit: Since the DMX512 single channel only has 8-bit (0-255) resolution, it cannot meet the high-precision control requirements of servo. This unit implements multi-channel cascading and functional domain reconstruction:

[0075] Multi-channel cascading: Extract consecutive data from the first DMX channel as the high byte and the second DMX channel as the low byte. For example, use CH3 as the speed high byte and CH4 as the speed low byte, and combine them to reconstruct a 16-bit high-resolution speed setting value from 0 to 65535. Similarly, multi-channel combinations can be used to generate high-resolution position commands.

[0076] Functional domain reconstruction: Extract data from the third DMX channel (e.g., CH2), compare it with a preset direction threshold (e.g., 128), and determine if it is less than 128 as reverse, and greater than or equal to 128 as forward, generating direction logic; extract data from the fourth DMX channel (e.g., CH1), compare it with a preset enable threshold (e.g., 128), and generate soft enable logic for controlling the Servo ON signal of the servo driver. This reconstructs the discrete light attribute stream into multi-dimensional servo control parameters.

[0077] 2. Kinematic Adaptation and Smoothing Unit: To avoid sudden changes in channel values ​​caused by the lighting technician pushing and pulling the DMX512 control console actuator, which could lead to rapid acceleration of the servo motor or mechanical shock, this unit implements incremental limiting and smooth transition processing. The specific smoothing algorithm is as follows: Within the current control cycle, obtain the reconstructed target pulse frequency f. target Compared with the actual output pulse frequency f of the previous cycle actual ; Calculate the frequency difference Δf=f target -factual Determine whether the absolute value of the difference |Δf| is greater than the preset maximum frequency increment Δf per single period. max (This value is set based on mechanical inertia constraints); if |Δf| > Δf max Then the final output frequency f of this cycle out =f actual +sign(Δf)×Δf max (i.e., stepping at maximum acceleration); If |Δf| ≤ Δf max Then the final output frequency f of this cycle out =f target The main control module determines the final output frequency f. out The pulse timer register value is updated in real time, thereby converting the step instruction into a smooth ramp trajectory that conforms to physical inertia.

[0078] 3. Cross-boundary safety interlock unit: To resolve the conflict between the "disconnection retention" logic of the DMX512 protocol and the "power failure shutdown" safety logic of industrial machinery, this unit implements hardware and software interlock arbitration:

[0079] Forced shutdown due to communication timeout: Real-time monitoring of the interval time of the Break signal in the DMX512 data frame. If it exceeds the preset communication timeout threshold (e.g., 1 second), it is determined that the communication has been lost, actively overturns the default hold state of the lighting protocol, sets the servo enable signal to an invalid level, and stops pulse output.

[0080] Hardware safety has the highest priority: external hardware emergency stop input signals and limit switch signals. These hardware safety signals have the highest priority. When any hardware signal is in a valid trigger state, the current value of the soft enable logic generated by the aforementioned cross-domain parameter reconstruction unit is unconditionally overridden, the pulse output channel is forcibly locked, and the motor is prohibited from running.

[0081] 4. The multi-dimensional servo control parameters of the mode switching unit also include the operating mode selection parameter. The main control module switches the output of different forms of control signals according to the value of the mode selection channel (such as CH6) in the DMX channel: select pulse plus direction control mode (timer generates pulse sequence, GPIO output direction), CW / CCW dual pulse control mode, or PWM control mode (output adjustable duty cycle waveform).

[0082] Since servo drives typically operate in highly turbulent industrial electrical environments, this module implements dual-ended isolation and differential drive adaptation:

[0083] The single-ended pulse output pin and direction pin of the main control module are first connected to the input of a high-speed digital isolator to achieve electrical isolation. The isolated signal is then connected to a differential line driver (such as a driver chip conforming to the RS422 standard), which converts the single-ended signal into two inverted differential pulse signals (A / B) and a differential direction signal. Finally, the signal is connected to the differential command input port of the servo driver. This design avoids the loss of high-speed pulses due to propagation delay or slow rise time.

[0084] Servo driver and motor module, represented by Huichuan servo driver, receives differential pulse, direction and enable control signals from output drive module, and drives servo motor to run along a smooth and safe trajectory according to internal parameter settings.

[0085] Furthermore, the specific reconstruction logic of the cross-domain parameter reconstruction unit includes:

[0086] Extract the first DMX channel data as the high byte and the second DMX channel data as the low byte, and combine them to generate a 16-bit or 32-bit high-resolution motion command.

[0087] Extract the data from the third DMX channel and compare it with a preset direction threshold to generate direction logic. Extract the data from the fourth DMX channel and compare it with a preset enable threshold to generate soft enable logic.

[0088] The specific reconstruction logic of the cross-domain parameter reconstruction unit is as follows: Since a single channel of the DMX512 has only 8 bits (0-255) resolution, this embodiment extracts the continuous first DMX channel data as the high byte and the second DMX channel data as the low byte. For example, CH3 is used as the speed high byte and CH4 as the speed low byte, and the data is combined and reconstructed into a 16-bit high-resolution speed setting value from 0 to 65535. Similarly, multiple channels can be combined to form a high-resolution position command. At the same time, the third DMX channel data (such as CH2) is extracted and compared with a preset direction threshold (such as 128) to generate direction logic. The fourth DMX channel data (such as CH1) is extracted and compared with a preset enable threshold (such as 128) to generate the soft enable logic (stop if less than 128, enable if greater than or equal to 128). This completes the cross-domain reconstruction from single-channel low-dimensional attributes to multi-channel multi-dimensional parameters.

[0089] Furthermore, the kinematic adaptation and smoothing unit performs the following smoothing algorithm:

[0090] Within the current control cycle, calculate the frequency difference between the target pulse frequency and the current actual output pulse frequency;

[0091] Determine whether the absolute value of the frequency difference is greater than the preset maximum frequency increment per single cycle;

[0092] If it is greater than, the current actual output pulse frequency plus the maximum frequency increment is used as the final output frequency for this cycle; if it is less than or equal to, the target pulse frequency is used as the final output frequency for this cycle.

[0093] Update the register value of the pulse generator based on the final output frequency.

[0094] In this embodiment, the kinematic adaptation and smoothing unit executes the following smoothing algorithm to achieve ramp limiting and maximum acceleration limiting: Within the current control cycle, the frequency difference between the target pulse frequency and the current actual output pulse frequency is calculated; it is determined whether the absolute value of the frequency difference is greater than a preset maximum frequency increment per cycle (this increment is determined by mechanical inertia constraints); if it is greater, the current actual output pulse frequency plus the maximum frequency increment is used as the final output frequency for this cycle; if it is less than or equal to, the target pulse frequency is used as the final output frequency for this cycle; the main control module updates the register value of the timer pulse generation unit according to the final output frequency. This algorithm effectively avoids servo acceleration caused by the instantaneous push and pull of the DMX push rod.

[0095] Furthermore, the specific interlocking logic of the cross-boundary safety interlocking unit includes:

[0096] The interval time of the Break signal in the DMX512 data frame is monitored in real time. If it exceeds the preset communication timeout threshold, the communication is determined to be lost, and the servo enable signal is actively set to an invalid level to overturn the default hold state of the DMX protocol.

[0097] The hardware emergency stop input signal and limit switch signal have the highest priority. When either hardware signal is in a valid trigger state, the current value of the soft enable logic is unconditionally overridden, and the pulse output channel is forcibly locked.

[0098] In this embodiment, the specific interlocking logic of the cross-domain safety interlocking unit includes: real-time monitoring of the interval time of the Break signal in the DMX512 data frame; if it exceeds the preset communication timeout threshold, it is determined that the communication has been lost, and the servo enable signal is actively set to an invalid level to overturn the default hold state of the DMX protocol (to prevent the motor from losing control and maintaining its original speed after the connection is broken); at the same time, the external hardware emergency stop input signal and the limit switch signal are given the highest priority. When any hardware signal is in a valid trigger state, the current value of the soft enable logic generated by the aforementioned cross-domain parameter reconstruction unit is unconditionally overridden, and the pulse output channel is forcibly locked to ensure that mechanical safety takes absolute priority over software instructions.

[0099] Furthermore, the signal output and isolation drive module includes a high-speed digital isolator and a differential line driver:

[0100] The single-ended pulse output pin and direction pin of the main control module are connected to the input of the high-speed digital isolator, and then connected to the differential line driver after isolation;

[0101] The differential line driver converts a single-ended signal into two inverted differential pulse signals (A / B) and a differential direction signal conforming to the RS422 standard, which are then connected to the differential command input port of the servo driver.

[0102] In this embodiment, the signal output and isolation drive module includes a high-speed digital isolator and a differential line driver: the single-ended pulse output pin and direction pin of the main control module are first connected to the input terminal of the high-speed digital isolator (such as a high-speed optocoupler or magnetic isolation chip) to achieve electrical isolation and enhance anti-interference capability; the isolated signal is then connected to the differential line driver (such as a driver chip conforming to the RS422 standard), which converts the single-ended signal into two inverted differential pulse signals (A / B) and a differential direction signal, and finally connects to the differential command input port of the servo driver. This design avoids pulse loss caused by propagation delay or slow rise time during long-distance transmission.

[0103] Furthermore, the signal access and conversion module includes an RS485 transceiver with magnetic or capacitive isolation and peripheral protection circuitry:

[0104] The RS485 transceiver connects to the UART peripheral of the main control module via a DMA ring buffer to identify the Break signal and start code of the DMX512 protocol.

[0105] The peripheral protection circuit includes a 120Ω terminating resistor located at the end of the bus, surge electrostatic protection devices, and a common-mode inductor.

[0106] In this embodiment, the signal access and conversion module includes an RS485 transceiver with magnetic isolation or capacitive isolation and peripheral protection circuitry: the RS485 transceiver is connected to the UART peripheral of the main control module through a DMA ring buffer, and accurately identifies the Break signal and start code of the DMX512 protocol by combining serial port idle interrupt and timer; the peripheral protection circuitry includes a 120Ω terminating matching resistor (to reduce signal reflection), surge electrostatic protection devices, and a common-mode inductor located at the end of the bus to improve the bus anti-interference capability in the complex electromagnetic environment of the stage.

[0107] Furthermore, the multi-dimensional servo control parameters include operating mode selection parameters. The main control module switches between output pulse plus direction control signal, CW / CCW dual pulse control signal or PWM duty cycle control signal according to the value of the mode selection channel in the DMX channel.

[0108] In this embodiment, the multi-dimensional servo control parameters include operating mode selection parameters. The main control module flexibly switches the form of the output control signal based on the value of the mode selection channel (e.g., CH6) in the DMX channel: when the pulse plus direction mode is selected, a pulse sequence is generated by the timer, and the GPIO outputs the direction; when the CW / CCW dual-pulse mode is selected, forward and reverse pulses are output from two channels; when the PWM mode is selected, an adjustable duty cycle waveform is output to adapt to the input interface types of different brands of servo drivers.

[0109] Secondly, the present invention provides a servo driver control method based on the DMX512 protocol, comprising:

[0110] Receives DMX512 differential signals and converts them into serial logic level signals;

[0111] The DMX512 data frame is parsed, and the low-resolution single-channel light attribute data is reconstructed into high-resolution motion commands through multi-channel cascading combination. The discrete channels are also reconstructed into multi-dimensional servo control parameters containing soft-enable logic according to functional domains.

[0112] Intercepting step-type target commands generated by the DMX512 protocol without a handshake mechanism, and performing incremental limiting and smooth transition processing on high-resolution motion commands based on mechanical inertia constraints;

[0113] When the DMX512 communication times out, the default hold logic of the lighting protocol is overturned and a shutdown is forced, and the soft enable logic is forcibly disabled when the hardware safety signal is triggered.

[0114] Based on the control parameters after smoothing and interlock arbitration, the output pulse, direction or PWM control signal is used to control the operation of the servo motor after isolation and differential drive adaptation.

[0115] Furthermore, the steps for incrementally limiting and smoothly transitioning commands based on mechanical inertia constraints specifically include:

[0116] Calculate the difference between the target pulse frequency of the current cycle and the actual output pulse frequency of the previous cycle;

[0117] Determine whether the absolute value of the difference is greater than the preset maximum frequency increment per single cycle;

[0118] If yes, then the actual output pulse frequency of the previous cycle plus the maximum frequency increment is used as the final output frequency of this cycle; if no, then the target pulse frequency is used as the final output frequency of this cycle.

[0119] In this embodiment, the steps of applying ramp and maximum acceleration limits to the command based on mechanical inertia constraints specifically include: calculating the difference between the target pulse frequency of the current cycle and the actual output pulse frequency of the previous cycle; determining whether the absolute value of the difference is greater than a preset maximum frequency increment per cycle; if so, adding the maximum frequency increment to the actual output pulse frequency of the previous cycle as the final output frequency of the current cycle; if not, using the target pulse frequency as the final output frequency of the current cycle. This step ensures that the frequency change rate does not exceed the limit, achieving a smooth transition.

[0120] Furthermore, the specific steps for forcibly disabling the soft enable logic include:

[0121] Real-time monitoring of the status of the hardware emergency stop input port and limit switch port;

[0122] When a valid level of a hardware emergency stop or limit signal is detected, the parsing result of the enable channel in the DMX channel data is skipped, the servo enable control variable is directly set to an invalid state, and the pulse output channel is simultaneously turned off.

[0123] In this embodiment, the step of forcibly disabling the soft enable logic specifically includes: real-time monitoring of the status of the hardware emergency stop input port and the limit switch port; when a valid level of the hardware emergency stop or limit signal is detected, skipping the parsing result of the enable channel (such as CH1) in the DMX channel data, directly setting the servo enable control variable to an invalid state, and simultaneously shutting down the pulse output channel. This step ensures that when the mechanical limit or emergency stop is triggered, even if the lighting engineer gives a run enable command on the control panel, the system can forcibly cut off the power output from the physical logic level.

[0124] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A servo drive control system based on the DMX512 protocol, characterized in that, include: The signal input and conversion module is used to receive DMX512 differential signals and convert them into serial logic level signals; The main control module, connected to the signal access and conversion module, internally incorporates cross-domain adaptation logic from lighting protocols to motion control. The main control module includes: a cross-domain parameter reconstruction unit, used to parse DMX512 data frames, reconstructing low-resolution single-channel lighting attribute data into high-resolution motion commands through multi-channel cascaded combination, and reconstructing discrete channels into multi-dimensional servo control parameters according to functional domains, including soft-enable logic; a kinematic adaptation and smoothing unit, connected to the cross-domain parameter reconstruction unit, used to intercept step-type target commands generated by the DMX512 protocol without a handshake mechanism, and perform incremental limiting and smooth transition processing on the high-resolution motion commands based on mechanical inertia constraints; a cross-domain safety interlock unit, used to overturn the default hold logic of the lighting protocol and force a shutdown when DMX512 communication times out, and to forcibly shield the soft-enable logic when a hardware safety signal is triggered; and a signal output and isolation drive module, connected to the main control module, used to output the smoothed and interlocked control signals after electrical isolation and power enhancement. The servo driver and motor module receive the control signals to perform mechanical motion.

2. The system according to claim 1, characterized in that, The specific reconstruction logic of the cross-domain parameter reconstruction unit includes: extracting continuous first DMX channel data as high byte, extracting second DMX channel data as low byte, and combining them to generate the 16-bit or 32-bit high-resolution motion command; extracting third DMX channel data and comparing the data with a preset direction threshold to generate direction logic; and extracting fourth DMX channel data and comparing it with a preset enable threshold to generate the soft enable logic.

3. The system according to claim 1, characterized in that, The kinematic adaptation and smoothing unit performs the following smoothing algorithm: within the current control cycle, calculates the frequency difference between the target pulse frequency and the current actual output pulse frequency; and determines whether the absolute value of the frequency difference is greater than the preset maximum frequency increment per cycle. If it is greater than the maximum frequency increment, then the current actual output pulse frequency plus the maximum frequency increment will be used as the final output frequency for this cycle. If it is less than or equal to, then the target pulse frequency will be used as the final output frequency for this cycle; Update the register value of the pulse generator based on the final output frequency.

4. The system according to claim 1, characterized in that, The specific interlocking logic of the cross-border safety interlocking unit includes: real-time monitoring of the interval time of the Break signal in the DMX512 data frame; if it exceeds the preset communication timeout threshold, it is determined that the communication has been lost, and the servo enable signal is actively set to an invalid level to overturn the default hold state of the DMX protocol; the hardware emergency stop input signal and the limit switch signal are given the highest priority, and when any hardware signal is in a valid trigger state, the current value of the soft enable logic is unconditionally overridden, and the pulse output channel is forcibly locked.

5. The system according to claim 1, characterized in that, The signal output and isolation drive module includes a high-speed digital isolator and a differential line driver: the single-ended pulse output pin and direction pin of the main control module are connected to the input terminal of the high-speed digital isolator, and after isolation, they are connected to the differential line driver; The differential line driver converts the single-ended signal into two-channel inverted differential pulse signals (A / B) and differential direction signals conforming to the RS422 standard, which are then connected to the differential command input port of the servo driver.

6. The system according to claim 1, characterized in that, The signal access and conversion module includes an RS485 transceiver with magnetic isolation or capacitive isolation and peripheral protection circuitry: the RS485 transceiver is connected to the UART peripheral of the main control module through a DMA ring buffer to identify the Break signal and start code of the DMX512 protocol; the peripheral protection circuitry includes a 120Ω terminating matching resistor, surge electrostatic protection device and common mode inductor located at the end of the bus.

7. The system according to claim 1, characterized in that, The multi-dimensional servo control parameters include operating mode selection parameters. The main control module switches between output pulse plus direction control signal, CW / CCW dual pulse control signal or PWM duty cycle control signal according to the value of the mode selection channel in the DMX channel.

8. A servo driver control method based on the DMX512 protocol, characterized in that, include: Receives DMX512 differential signals and converts them into serial logic level signals; The system parses DMX512 data frames, reconstructs low-resolution single-channel lighting attribute data into high-resolution motion commands through multi-channel cascading, and reconstructs discrete channels into multi-dimensional servo control parameters including soft-enable logic according to functional domains. It intercepts step-type target commands generated by the DMX512 protocol without a handshake mechanism and performs incremental limiting and smooth transition processing on the high-resolution motion commands based on mechanical inertia constraints. When DMX512 communication times out, it overturns the default hold logic of the lighting protocol to force a shutdown, and forcibly disables the soft-enable logic when a hardware safety signal is triggered. Based on the smoothed and interlocked arbitration-derived control parameters, it outputs pulse, direction, or PWM control signals, which are then isolated and differentially driven to control the servo motor.

9. The method according to claim 8, characterized in that, The steps of incrementally limiting and smoothing the transition of the command based on mechanical inertia constraints specifically include: calculating the difference between the target pulse frequency of the current cycle and the actual output pulse frequency of the previous cycle; determining whether the absolute value of the difference is greater than the preset maximum frequency increment of a single cycle; if so, adding the maximum frequency increment to the actual output pulse frequency of the previous cycle as the final output frequency of the current cycle; if not, using the target pulse frequency as the final output frequency of the current cycle.

10. The method according to claim 8, characterized in that, The steps of the forced shielding soft enable logic specifically include: real-time monitoring of the status of the hardware emergency stop input port and the limit switch port; when a valid level of the hardware emergency stop or limit signal is detected, skipping the parsing result of the enable channel in the DMX channel data, directly setting the servo enable control variable to an invalid state, and simultaneously shutting down the pulse output channel.

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