A control method, system and related device for an external robot joint drive board

Abstract

The application discloses a robot joint driving board external control method, system and related device, which is used for realizing the externalization of the driving board to optimize the heat dissipation and space layout of the robot joint, and ensuring the timing coordination of the signal interaction between the driving board and the joint side. The method comprises the following steps: the driving board runs based on a preset control period, and sends a synchronization signal to the acquisition board through a synchronization signal channel at the starting stage of each control period; the acquisition board performs a clock synchronization operation in response to receiving the synchronization signal, so as to calibrate the internal working timing of the acquisition board; the acquisition board collects joint sensor data after performing the clock synchronization operation, and sends the joint sensor data to the driving board through a data communication channel; and the driving board performs timing alignment processing on the joint sensor data based on the timing corresponding relationship between the sending time of the synchronization signal and the receiving time of the joint sensor data, and completes joint control calculation.

Description

Technical Field

[0001] This application relates to the field of robotics technology, and in particular to a control method, system and related device for an externally mounted robot joint drive plate. Background Technology

[0002] Currently, drive boards for robot joints are typically mounted directly inside the joint body. While this built-in design offers a simple and reliable connection, it has significant limitations in certain application scenarios. On one hand, as robots become smaller and more compact, the internal space of some joints is extremely limited, making it impossible to accommodate a large drive board. On the other hand, for joints that require high power density, the built-in drive board generates significant heat under heavy loads, and insufficient heat dissipation will directly limit the joint's power output.

[0003] To address the aforementioned space and heat dissipation issues, one option is to move the drive board from inside the joint and install it externally. However, directly moving the drive board to the remote end introduces complex connectivity problems: a typical robot joint usually includes three-phase motor wires, dual encoder wires, thermistor wires, and torque sensor wires, often totaling 17 or more cables. Using traditional direct wiring methods, extending such a large number of wires directly to the external drive board would significantly increase the complexity of internal wiring and space requirements. Furthermore, long-distance cable transmission can severely impact signal quality, especially for sensitive signals such as torque sensor sampling lines. Excessive cable length can cause voltage sampling signal distortion, leading to a significant reduction in the robot's control accuracy and performance. Summary of the Invention

[0004] This application provides a control method, system, and related device for externally mounted robot joint drive boards, which optimizes robot joint heat dissipation and spatial layout while ensuring the timing coordination of signal interaction between the drive board and the joint side.

[0005] The first aspect of this application provides a control method for an externally mounted robot joint drive board. The robot includes a drive board disposed outside the joint and a data acquisition board disposed on the side of the joint. The drive board and the data acquisition board are connected by a power line and a ground line. The drive board supplies power to the data acquisition board through the power line. A data communication channel and a synchronization signal channel are provided between the drive board and the data acquisition board. The power line, the ground line, and the signal transmission lines constituting the data communication channel and the synchronization signal channel are integrated into the same composite cable.

[0006] The control method includes:

[0007] The driver board operates based on a preset control cycle, and sends a synchronization signal to the acquisition board through the synchronization signal channel at the beginning of each control cycle.

[0008] In response to receiving the synchronization signal, the acquisition board performs a clock synchronization operation to calibrate the internal working timing of the acquisition board;

[0009] After performing the clock synchronization operation, the acquisition board acquires joint sensor data and sends the joint sensor data to the driver board through the data communication channel.

[0010] The drive board performs timing alignment processing on the joint sensor data based on the timing correspondence between the transmission time of the synchronization signal and the reception time of the joint sensor data, and completes the joint control calculation.

[0011] Optionally, in response to receiving the synchronization signal, the acquisition board performs a clock synchronization operation, including:

[0012] The acquisition board monitors the synchronization signal channel;

[0013] When the trigger edge of the synchronization signal is detected, the acquisition board clears the internal timer counter and immediately triggers the data acquisition process corresponding to the current control cycle.

[0014] The data collected from the joint sensors includes:

[0015] In the data acquisition process, the acquisition board sets the trigger time of the synchronization signal as the start time of the data sampling period, and performs the acquisition operation of joint sensor data within the data sampling period to eliminate the phase drift between the acquisition board and the drive board.

[0016] Optionally, the control method further includes:

[0017] When the acquisition board does not detect the trigger edge of the synchronization signal within the current control cycle, the acquisition board continues to execute the data acquisition process based on the internal working timing calibrated after the previous effective control cycle.

[0018] Optionally, the driver board performs timing alignment processing on the joint sensor data based on the timing correspondence between the transmission time of the synchronization signal and the reception time of the joint sensor data, including:

[0019] The driver board acquires a pre-configured fixed hysteresis period number N, which is used to characterize the timing lag of the joint sensor data reception time relative to the synchronization signal transmission time.

[0020] The drive board marks the received joint sensor data as historical state data of the Nth cycle before the current control cycle according to the fixed hysteresis cycle number N, thereby establishing a time mapping between the joint sensor data and the current control cycle to complete the timing alignment between the joint sensor data and the control cycle.

[0021] Optionally, the control method further includes:

[0022] During operation, the drive board monitors in real time the time difference between the actual reception time of the joint sensor data and the transmission time of the synchronization signal.

[0023] When the deviation between the time difference and the theoretical time difference corresponding to the fixed lag period number N exceeds a preset threshold, the drive board recalculates and updates the fixed lag period number N based on the current time difference.

[0024] Optionally, the process of performing joint control calculations includes:

[0025] The drive board acquires the real-time rotational speed of the robot joint within the current control cycle, and calculates the angular position change of the joint sensor data during the transmission delay based on the real-time rotational speed and the duration corresponding to the fixed lag period N.

[0026] The drive board superimposes the change in angle position onto the position information in the historical state data to obtain the estimated joint position value for the current control cycle, and generates motor drive commands based on the estimated joint position value.

[0027] Optionally, the synchronization signal channel and the data communication channel are set up independently, and both adopt differential signal transmission.

[0028] Optionally, the synchronization signal channel and the data communication channel share the same set of physical lines;

[0029] The driver board operates based on a preset control cycle, and at the beginning of each control cycle, it sends a synchronization signal to the acquisition board through the synchronization signal channel, including:

[0030] The driver board operates based on a preset control cycle, and at the beginning of each control cycle, it sends a synchronization signal to the acquisition board on the physical line by time-division multiplexing or by embedding a synchronization identifier in the communication frame header.

[0031] Optionally, the acquisition board is connected to a sensor group, which includes at least one of a motor-end encoder, a reducer-end encoder, a thermistor, and a torque sensor.

[0032] After performing the clock synchronization operation, the acquisition board acquires joint sensor data, including:

[0033] After performing the clock synchronization operation, the acquisition board synchronously reads the signal values ​​of each sensor in the sensor group through the onboard interface, and performs unified formatting processing on the read signal values.

[0034] A second aspect of this application provides a control system for an externally mounted robot joint drive board. The control system includes a drive board disposed outside the robot joint and a data acquisition board disposed on the side of the joint. The drive board and the data acquisition board are connected by a power line and a ground line. The drive board supplies power to the data acquisition board through the power line. A data communication channel and a synchronization signal channel are provided between the drive board and the data acquisition board. The power line, the ground line, and the signal transmission lines constituting the data communication channel and the synchronization signal channel are integrated into the same composite cable.

[0035] The drive board is used to operate based on a preset control cycle, and sends a synchronization signal to the acquisition board through the synchronization signal channel at the beginning of each control cycle.

[0036] The acquisition board is used to perform a clock synchronization operation in response to receiving the synchronization signal, so as to calibrate the internal working timing of the acquisition board;

[0037] The acquisition board is also used to acquire joint sensor data after performing the clock synchronization operation, and send the joint sensor data to the driver board through the data communication channel;

[0038] The drive board is also used to receive the joint sensor data, and based on the timing correspondence between the transmission time of the synchronization signal and the reception time of the joint sensor data, to perform timing alignment processing on the joint sensor data and complete the joint control calculation.

[0039] As can be seen from the above technical solutions, this application has the following advantages:

[0040] The driver board operates under a preset control cycle and sends a synchronization signal at the beginning of each control cycle, ensuring that the start time of the control cycle is clearly transmitted to the acquisition board on the joint side. Upon receiving the synchronization signal, the acquisition board performs a clock synchronization operation, calibrating its internal operating timing with the start time of the control cycle indicated by the synchronization signal. After completing the clock synchronization operation, it acquires joint sensor data and sends it to the driver board. Upon receiving the joint sensor data, the driver board performs timing alignment processing on the joint sensor data based on the timing correspondence between the transmission time of the synchronization signal and the reception time of the joint sensor data, and completes joint control calculations accordingly.

[0041] Through the above control process, the control cycle of the drive board, the data acquisition timing of the acquisition board, and the data transmission process of the joint sensors form a stable and consistent mapping relationship in the time dimension. This enables the drive board, which is externally placed in the joint system architecture, to perform control calculations based on the joint state data corresponding to the current control cycle. This ensures the continuity and consistency of the robot joint control process in the time dimension while optimizing the robot joint heat dissipation and spatial layout. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the connection structure between the robot drive plate and the joint in the prior art;

[0044] Figure 2 This is a schematic diagram of the connection structure between the drive plate and the joint after the acquisition plate is introduced in this application;

[0045] Figure 3 A schematic flowchart of an embodiment of the control method for an externally mounted robot joint drive board provided in this application;

[0046] Figure 4 A schematic flowchart of another embodiment of the control method for an externally mounted robot joint drive plate provided in this application;

[0047] Figure 5 This is a schematic diagram of the communication timing between the driver board loop calculation and the encoder;

[0048] Figure 6 This is a schematic diagram of the communication timing between the driver board and the acquisition board;

[0049] Figure 7 This is a schematic diagram of an embodiment of the control system with an externally mounted robot joint drive board provided in this application. Detailed Implementation

[0050] This application provides a control method, system, and related device for externally mounted robot joint drive boards, which optimizes robot joint heat dissipation and spatial layout while ensuring the timing coordination of signal interaction between the drive board and the joint side.

[0051] In the following description, the control method and related structures of the robot joint drive plate externally involved in this application will be described with reference to the accompanying drawings. It should be understood that the description is only used to illustrate the technical concept and implementation of this application and does not constitute a limitation on the scope of protection of this application. Those skilled in the art can make various equivalent substitutions or modifications to the structural form, connection method, signal transmission method and control flow without departing from the technical concept of this application, and all such substitutions or modifications should be considered to fall within the scope of protection of this application.

[0052] Please see Figure 1 , Figure 1 This is a schematic diagram of the wiring structure between the robot drive plate and the joint in existing technology. Figure 1 As is known, in traditional architectures, the drive board typically establishes a point-to-point physical connection with various actuators and sensors inside the joint. These connections include three-phase motor lines for driving the motor, as well as power lines and differential communication lines for connecting the encoders at the motor and reducer ends, respectively. In addition, the joint usually needs to accommodate thermistor signal lines (usually two or four) for temperature detection. If the joint integrates a torque sensor, multiple additional transmission lines for analog signal acquisition are required. This architecture results in a large number of independent cables with different functions between the drive board and the joint. If the drive board is placed externally under this architecture, it will not only significantly increase the complexity and space occupation of the robot's internal wiring, but long-distance transmission can also easily lead to a decrease in the signal-to-noise ratio of analog signals such as those from torque sensors, affecting sampling quality. These problems are particularly prominent when dealing with multi-joint systems.

[0053] Please see Figure 2 , Figure 2 This is a schematic diagram of the connection structure between the drive plate and the joint after the acquisition plate is introduced in this application. Figure 2As shown, in the system architecture of this application where the robot uses an externally mounted drive board, the drive board is located in the external space away from the joint body and is mainly responsible for joint motion control calculations and motor power drive. A data acquisition board is located on the joint side (i.e., inside or adjacent to the joint) to collect and preprocess joint sensor signals and interact with the drive board via digital signals. Electrically, the drive board and data acquisition board are connected via a power line (VDD) and a ground line (GND), with the drive board providing operating voltage to the acquisition board. Simultaneously, a data communication channel for transmitting packaged sensor data and a synchronization signal channel for establishing a unified timing reference are established between them. In this application, the power line, ground line, and signal transmission lines constituting the data communication channel and synchronization signal channel are integrated into a single composite cable. Based on this architecture, the physical connection between the drive board and the joint is simplified to two parts: a high-power three-phase line for motor drive and the aforementioned composite cable connecting the drive board and the data acquisition board. Because the acquisition board is highly integrated and compact, it can be directly built into the joint, allowing the originally complex sensor wiring harness to be arranged inside the joint, with only a small number of cables interacting externally. This structure effectively reduces wiring difficulty while allowing the driver board to be externally mounted to optimize heat dissipation and space layout.

[0054] The following provides a detailed description of the external control method for the robot joint drive board provided in this application. Please refer to [link / reference]. Figure 3 , Figure 3 An embodiment of the control method for an externally mounted robot joint drive plate provided in this application includes:

[0055] 301. The driver board operates based on a preset control cycle and sends a synchronization signal to the acquisition board through the synchronization signal channel at the beginning of each control cycle.

[0056] In this embodiment, the drive board is disposed outside the robot joint and is used to periodically perform joint control-related calculations and update control commands. To ensure the stability of joint control, the drive board operates according to a pre-set control cycle. This control cycle is the time interval for the drive board to repeatedly perform control calculations, i.e., the time required to complete one complete "sampling-calculation-output" closed-loop control process. Its length can be set according to the dynamic response requirements of the robot joint. For example, in industrial robot applications, this cycle is usually set to the microsecond level (e.g., 100µs) to ensure real-time response to the joint motion state. During the continuous operation of the drive board, each control cycle has a clear start phase, which is used to mark the beginning of a new round of control calculations.

[0057] At the beginning of each control cycle, the driver board sends a synchronization signal through a synchronization signal channel between itself and the joint-side acquisition board. This synchronization signal channel transmits timing information related to the control cycle between the driver board and the acquisition board, and the transmitted synchronization signal corresponds to the start time of the current control cycle for the driver board. For example, when entering a new control cycle, the driver board outputs a synchronization flag through the synchronization signal channel to indicate that the control cycle has begun.

[0058] By sending a synchronization signal at the beginning of each control cycle, the driver board explicitly transmits the timing of its control cycle to the acquisition board on the joint side, enabling the acquisition board to sense the starting boundary of the driver board's control cycle. It should be noted that this synchronization signal does not carry specific joint sensor data; rather, it serves as a time reference for subsequent joint sensor data acquisition and transmission, thus ensuring a consistent timing basis between the driver board and the acquisition board within the external driver board architecture.

[0059] 302. Upon receiving a synchronization signal, the acquisition board performs a clock synchronization operation to calibrate its internal operating timing.

[0060] In this embodiment, the acquisition board is located on the robot joint side and is used to cooperate with the drive board to process and transmit joint-related signals. When the acquisition board receives a synchronization signal sent by the drive board through the synchronization signal channel, it indicates that the drive board has entered a new control cycle. After detecting the synchronization signal, the acquisition board responds by performing a clock synchronization operation to establish a correspondence between the internal working timing of the acquisition board and the control cycle of the drive board.

[0061] Specifically, clock synchronization is used to adjust the time base of various workflows within the acquisition board, ensuring that its internal timing references for data processing and scheduling match the start time of the control cycle indicated by the synchronization signal. In practical applications, the acquisition board typically relies on its internal timing units to schedule various processing tasks. Without synchronization, this internal timing may gradually deviate from the control cycle of the driver board due to independent operation. By performing clock synchronization upon receiving the synchronization signal, the acquisition board can calibrate its internal timing with the synchronization signal as a reference, thereby eliminating the time deviation between it and the driver board and ensuring that subsequent operations are based on a unified timeline.

[0062] 303. After performing clock synchronization, the acquisition board acquires joint sensor data and sends the joint sensor data to the driver board through the data communication channel.

[0063] In this embodiment, after completing the clock synchronization operation, the acquisition board enters the working state corresponding to the current control cycle and acquires joint sensor data in this state. The joint sensor data characterizes the actual state of the robot joints during operation, specifically including sensing information reflecting joint position, rotational speed, temperature, or force. Since the acquisition board has already calibrated its internal working timing based on the synchronization signal in step 302, the acquisition time of the joint sensor data can establish a clear time correspondence with the control cycle of the drive board; that is, the acquired joint sensor data reflects the physical state of the joint under a unified timing reference.

[0064] During operation, after each clock synchronization operation, the acquisition board reads data from the sensors located on the joint side according to the calibrated internal working sequence, thereby acquiring joint sensor data reflecting the current joint state. The acquired joint sensor data is then transmitted to the driver board via a data communication channel between the acquisition board and the driver board. This data communication channel carries the transmission of joint sensor data, and its transmission process coordinates with the transmission of synchronization signals, enabling the driver board to determine the corresponding control cycle based on the previously sent synchronization signals when it receives the joint sensor data.

[0065] In its implementation, the acquisition board is connected to a set of sensors characterizing the joint's operating state. This sensor set can be configured according to the specific joint structure and functional requirements, and includes at least one or more of the following: a motor-end encoder, a reducer-end encoder, a thermistor, and a torque sensor. The motor-end encoder reflects the instantaneous position or speed information of the motor rotor; the reducer-end encoder acquires the output shaft position information after reduction; the thermistor monitors the temperature of key components inside the joint; and the torque sensor senses the load or output torque experienced by the joint during operation. In step 303, after the acquisition board completes clock synchronization under the aforementioned synchronization signal, its internal operating timing is uniformly aligned to the starting reference of the current control cycle. Based on this, the acquisition board enters the joint sensor data acquisition stage. Specifically, the acquisition board reads the signals from each sensor in the connected sensor set at the same synchronization moment through its onboard interface. For example, within a control cycle, the acquisition board can simultaneously read the angle or pulse count value from the motor-end encoder, the output shaft position from the reducer-end encoder, the temperature sampling value from the thermistor, and the corresponding torque measurement signal from the torque sensor. Since the above reading operations all occur within a unified time window after clock synchronization, the data from various sensors have a consistent reference standard in the time dimension, thus avoiding timing deviations caused by inconsistent sampling times between different sensor data. After reading the signals from each sensor, the acquisition board also performs a unified formatting process on the acquired signal values. This formatting process may include, but is not limited to: performing dimension conversion, numerical encapsulation, timestamp association, or protocol encapsulation on the raw signals from different types of sensors to make them conform to the unified data structure requirements for data communication with the driver board.

[0066] 304. Based on the timing correspondence between the transmission time of the synchronization signal and the reception time of the joint sensor data, the driver board performs timing alignment processing on the joint sensor data and completes the joint control calculation.

[0067] In this embodiment, after receiving the joint sensor data sent by the acquisition board through the data communication channel, the driver board processes the joint sensor data and completes the joint control calculation. Since the driver board has sent a synchronization signal at the beginning of each control cycle in the aforementioned steps, and the acquisition board acquires and sends the joint sensor data after completing the clock synchronization operation, the driver board can establish a stable timing correspondence between the transmission time of the synchronization signal and the reception time of the joint sensor data.

[0068] During operation, the driver board determines the timing of the synchronization signal transmission when entering the current control cycle. When the driver board subsequently receives joint sensor data, it can determine the control cycle position on the time axis based on the correspondence between the data reception time and the synchronization signal transmission time. Based on this timing correspondence, the driver board performs timing alignment processing on the joint sensor data, establishing a logically consistent time mapping between the received joint sensor data and the control cycle currently being executed by the driver board. After timing alignment, the driver board performs joint control calculations based on the time-aligned joint sensor data and generates corresponding control commands to drive joint movement.

[0069] Through the above processing method, even with the drive board externally placed in the joint system architecture, it can still complete control calculations based on joint state information consistent with the control cycle, so that the joint control process maintains continuity and consistency in the time dimension, thereby supporting the stable control of the robot joint during operation.

[0070] In this embodiment, the drive board operates under a preset control cycle and sends a synchronization signal at the beginning of each control cycle, so that the start time of the control cycle of the drive board can be clearly transmitted to the acquisition board on the joint side. After receiving the synchronization signal, the acquisition board performs a clock synchronization operation to calibrate its internal working timing with the start time of the control cycle indicated by the synchronization signal. After completing the clock synchronization operation, it acquires joint sensor data and sends it to the drive board. After receiving the joint sensor data, the drive board performs timing alignment processing on the joint sensor data based on the timing correspondence formed between the sending time of the synchronization signal and the receiving time of the joint sensor data, and completes the joint control calculation on this basis.

[0071] Through the above control process, the control cycle of the drive board, the data acquisition timing of the acquisition board, and the data transmission process of the joint sensors form a stable and consistent mapping relationship in the time dimension. This enables the drive board, which is externally placed in the joint system architecture, to perform control calculations based on the joint state data corresponding to the current control cycle. This ensures the continuity and consistency of the robot joint control process in the time dimension while optimizing the robot joint heat dissipation and spatial layout.

[0072] The following provides a detailed description of the external control method for the robot joint drive board provided in this application. Please refer to [link / reference]. Figure 4 , Figure 4 Another embodiment of the control method for an externally mounted robot joint drive plate provided in this application includes:

[0073] 401. The driver board operates based on a preset control cycle and sends a synchronization signal to the acquisition board through the synchronization signal channel at the beginning of each control cycle.

[0074] In this embodiment, step 401 is similar to step 301 in the previous embodiment, and will not be described again here.

[0075] 402. The acquisition board monitors the synchronization signal channel. When the trigger edge of the synchronization signal is detected, the acquisition board clears the internal timer counter and immediately triggers the data acquisition process corresponding to the current control cycle.

[0076] In this embodiment, when the acquisition board is in standby or running state, its internal logic maintains real-time monitoring of the synchronization signal channel. This monitoring function is typically implemented using the hardware capture circuitry inside the acquisition board or a high-priority external interrupt interface to ensure microsecond-level response capability to signal changes. When a preset transition occurs on the level state of the synchronization signal channel, such as a rising edge from low to high or a falling edge from high to low, this transition constitutes the trigger edge of the synchronization signal. This trigger edge physically represents the arrival of the synchronization signal and can serve as a physical marker of the start time of a new control cycle for the driver board.

[0077] Once the trigger edge is detected, the acquisition board responds immediately, performing a forced zeroing or reset operation on its internal timer / counter used to maintain local timing. This counter-zeroing action essentially aligns the zero point of the acquisition board's internal time axis to the instant the synchronization signal arrives, thus physically eliminating the random time deviation accumulated due to the operation of independent clock sources. Simultaneously with the counter-zeroing, the acquisition board immediately triggers and enters the data acquisition process corresponding to the current control cycle. This process can be implemented by calling a preset interrupt service routine (ISR). Through this hardware synchronization mechanism, the acquisition board ensures that all subsequent sensor data acquisition actions are initiated on a unified timing reference after eliminating phase drift with the driver board, thereby avoiding random drift of the data sampling time relative to the control cycle caused by clock asynchrony at both ends.

[0078] In some specific embodiments, considering the potential for abnormal situations such as electromagnetic interference, cable contact jitter, or momentary signal shielding in the actual operation of industrial robots, a fault-tolerant handling mechanism can be configured for the loss of synchronization signals. Specifically, when the acquisition board does not detect the trigger edge of the synchronization signal within the current control cycle, the acquisition board continues to execute the data acquisition process based on the internal working timing calibrated from the previous valid control cycle.

[0079] In this mode, the acquisition board continues to operate based on the internal timing established by the previous effective control cycle, i.e., the cycle in which the synchronization signal was most recently successfully received and calibration was completed. Because the timing components such as the crystal oscillator inside the acquisition board have high short-term frequency stability, the cumulative phase drift between its internal timing and the drive board's control cycle is usually within an acceptable error range during the short period of loss of the external synchronization signal. Therefore, based on this calibrated internal timer / counter, the acquisition board automatically triggers the data acquisition process at the calculated start time of the theoretical control cycle. This ensures that the acquisition and transmission links of joint sensor data can remain continuously operational even in the event of a momentary failure in the external synchronization link, avoiding data interruption in the control loop or unexpected sudden stops of the robot due to a single loss of synchronization signal. This improves the robustness and reliability of robot joint control under complex working conditions.

[0080] 403. In the data acquisition process, the acquisition board sets the trigger time of the synchronization signal as the start time of the data sampling period, and performs the acquisition operation of joint sensor data within the data sampling period to eliminate the phase drift between the acquisition board and the drive board.

[0081] After the data acquisition process is initiated, the acquisition board determines the timing reference for the current data sampling period, defining the trigger moment of the captured synchronization signal as the zero point of this sampling period. Within this unified timing framework, the acquisition board performs data reading operations on the sensor group connected to the joint side through the onboard sensor interface circuit. The sensor group typically includes a motor-side encoder for feedback of the motor rotor position, a reducer-side encoder for feedback of the load position, a thermistor for monitoring winding temperature, and a torque sensor for sensing joint load.

[0082] In actual execution, the acquisition board can employ parallel reading or serial polling within extremely short time intervals to ensure that the sampling time of all sensor data is immediately adjacent to the synchronization trigger time. By strictly limiting the starting point of data sampling to the trigger edge of the synchronization signal, this step effectively solves the common clock asynchrony problem in distributed control architectures. In existing technologies that do not incorporate this mechanism, since the acquisition board and the driver board each use independent crystal oscillators as clock sources, a frequency deviation between them is inevitable. Over long periods of operation, this can cause random phase drift of the sampling time relative to the control cycle, resulting in inconsistent sampling times. This embodiment, however, forces the sampling start time to align in each cycle, making each round of data acquisition equivalent to a synchronization, thereby periodically clearing the accumulated phase error to zero. The acquired joint sensor data always maintains a fixed phase relationship with the control cycle of the driver board, thus eliminating the impact of phase drift on control accuracy.

[0083] 404. The acquisition board sends the joint sensor data to the driver board through the data communication channel;

[0084] In this embodiment, step 404 is similar to step 303 in the previous embodiment, and will not be described again here.

[0085] 405. The driver board obtains the pre-configured fixed lag period number N. The fixed lag period number N is used to characterize the timing lag of the joint sensor data reception time relative to the synchronization signal transmission time.

[0086] In this embodiment, before processing the joint sensor data, the driver board needs to call the internally stored fixed hysteresis cycle number N. The setting of this parameter N is based on the parallel timing strategy between the driver board's loop calculation and encoder communication. To further understand the necessity and physical meaning of this fixed hysteresis cycle number N, the following will combine... Figure 5 To explain, Figure 5 A timing diagram illustrating the communication between the driver board loop calculation and the encoder:

[0087] In high-performance robot joint servo control, motor control algorithms are extremely time-sensitive. The typical control loop cycle, i.e., the control cycle of this application, is usually set to an extremely short duration, such as 100µs or even shorter. However, within this limited 100µs, the main processor of the driver board not only needs to complete complex kinematic and dynamic calculations but also handle various safety monitoring tasks, resulting in limited computing resources. Typically, less than 50% of the time window is available for core loop calculations. Meanwhile, communication between the acquisition board and the driver board is a relatively time-consuming physical process; completing a full data packet transmission often takes tens of microseconds. If the driver board suspends the program after sending a synchronization signal to wait for the current cycle's sampling data to return before performing calculations, computation time will be wasted on communication waiting, thus failing to meet the real-time requirements of the high-frequency control loop. Therefore, this embodiment adopts the following... Figure 5 The communication timing strategy is as follows: When the driver board enters the loop calculation process of a certain control cycle, it does not wait for the current real-time sampling result, but directly obtains the feedback data that has been completed in the previous round of communication and stored in the buffer, and uses it for the control calculation of the current cycle. At the same time, the driver board immediately sends a synchronization signal to the acquisition board, thereby initiating a new round (round A) communication request, but does not wait for the return of the round A data within the current cycle. Subsequently, when the driver board enters the next control cycle, it obtains the round A data returned by the aforementioned round A communication from the buffer, uses it for the loop calculation of the next cycle, and simultaneously initiates the next round (round B) communication request.

[0088] Similarly, in this processing mode, the joint sensor data (such as A-wheel data) used by the drive board in any control cycle is actually triggered and sampled by the previous control cycle (the cycle that initiates A-wheel communication). This means that there is a fixed periodic delay between the time when the data is used and the time when the data is triggered and collected. This fixed lag period number N is used to quantify this fixed delay cycle number.

[0089] 406. The drive board marks the received joint sensor data as the historical state data of the Nth cycle before the current control cycle based on the fixed lag cycle number N, thereby establishing a time mapping between the joint sensor data and the current control cycle to complete the timing alignment between the joint sensor data and the control cycle.

[0090] In this embodiment, after determining the fixed hysteresis cycle number N, the driver board performs corresponding timing marking processing on the received joint sensor data. This processing is used to define the logical position of the joint sensor data on the time axis within the driver board, enabling the data to form a deterministic time correspondence with the current control cycle.

[0091] As in step 405, after introducing a data acquisition board between the drive board and the joint, the acquisition board takes over the direct communication task with the underlying sensors such as the encoder inside the joint. To balance data transmission and processing efficiency within high-frequency control cycles, the acquisition board adopts a periodic pipelined communication strategy. That is, within the current control cycle, it reads data from the previous cycle's completed communication and simultaneously initiates a new round of data acquisition requests. Therefore, the joint sensor data held by the acquisition board naturally has a fixed delay of at least one control cycle relative to its acquisition trigger time. Furthermore, the data communication between the drive board and the acquisition board also adopts a control cycle-based scheduling method, so that the joint sensor data received by the drive board in a certain control cycle actually corresponds to the data acquired and transmitted back by the acquisition board in an earlier cycle. Thus, on the drive board side, an overall transmission delay is formed by the superposition of two levels of periodic communication. Under ideal synchronization, this delay can be quantified as a fixed number of control cycles, i.e., a fixed lag cycle number N (e.g., two control cycles).

[0092] However, in the absence of a unified timing reference, the driver board and the acquisition board operate independently based on their respective clock sources. The actual physical timing of their entry into the periodic processing flow may deviate, varying within a control cycle and accumulating over time. When this timing deviation accumulates to a complete control cycle, the acquisition board may prematurely enter a new processing cycle, causing unreturned data to be overwritten or discarded. This results in discontinuous jumps in the data received by the driver board on the timeline, thus compromising the deterministic nature of the transmission delay. To address this, this embodiment employs a synchronization signal sent by the driver board at the beginning of each control cycle, and the acquisition board calibrates its internal timing based on this synchronization signal. This ensures that the driver board and the acquisition board maintain consistency at the start of the cycle, thereby locking the originally time-drifting uncertain delay into a stable and repeatable fixed lag period N. Based on this stable timing, the driver board, in this step, uses the fixed lag period N to retrospectively mark the received joint sensor data, explicitly identifying it as the historical state data corresponding to the Nth cycle prior to the current control cycle.

[0093] The following is combined Figure 6 The necessity and implementation principle of timing alignment are explained. Figure 6 This is a schematic diagram of the communication timing between the driver board and the acquisition board. (Example:) Figure 6 As shown, the acquisition board first obtains the A-round data in the lower-level interrupt and initiates the B-round communication; subsequently, the driver board obtains the A-round data through communication in the upper-level interrupt. This transmission mechanism causes the A-round data currently obtained by the driver board to lag behind its generation time in physical time. Without the synchronization mechanism in step 402 of this embodiment, as... Figure 6 As indicated by the interrupt time difference, there is a phase deviation between the control cycle (upper-layer square wave) of the driver board and the data acquisition cycle (lower-layer square wave) of the acquisition board. Since the two boards use independent crystal oscillators as clock sources, this interrupt time difference is a random and unpredictable variable that fluctuates between 0 and 100µs (i.e., one complete control cycle). Furthermore, due to slight differences in hardware clock frequencies, this time difference will slowly drift over time. When this interrupt time difference continues to drift and accumulates to cross a cycle boundary, it can cause frame skipping or overlap in data sampling. For example, if the acquisition board's clock is slightly faster, it may enter the next acquisition round before the driver board initiates reading, causing old data to be overwritten. This results in the total system delay oscillating uncertainly between "N cycles" and "N+1 cycles" (e.g., 200µs to 300µs). This uncertain delay fluctuation can cause non-physical abrupt jitter in the position and velocity data received by the driver board, thereby disrupting the stability of the control loop.

[0094] To address the aforementioned technical problems, this embodiment can forcibly eliminate them through the synchronization signal mechanism in step 402. Figure 6 The interrupt time difference. Specifically, the synchronization signal sent by the driver board forces the acquisition board to maintain phase lock with the driver board's "enter data acquisition interrupt" time and the driver board's "enter loop interrupt" time, that is... Figure 6 The rising edges of the upper and lower square waves are forcibly aligned. Under this synchronization reference, the system's uncertain delay is eliminated, and the total data transmission lag is strictly locked to a fixed number of physical beats. In the timing relationship shown in this embodiment, this fixed lag is confirmed as N cycles. Based on this determined timing relationship, the driver board performs a logic marking operation in step 406: when the driver board receives A-cycle data in the current control cycle, according to the preset fixed lag cycle number N, it backtracks and positions the A-cycle data on the time axis, clearly marking it as the historical state data of the Nth cycle before the current moment. In this way, the driver board accurately maps the received sensor data from the receiving moment back to its generation moment, establishing a definite timing correspondence, thereby completing the timing alignment of the joint sensor data and the control cycle.

[0095] For ease of explanation, we can use N=2 as a typical example to illustrate the fixed lag period N. This is the most common structure when both the driver board and the acquisition board employ a single-cycle pipelined communication strategy, and there is only one acquisition board relay between them. However, in practical engineering applications, the value of N depends on the data processing and communication scheduling methods of the driver board and the acquisition board. For example, when additional data buffering, queue scheduling, or multi-sensor polling mechanisms are introduced on the acquisition board side, the joint sensor data may be delayed for several control cycles before being sent to the driver board. Or, when the driver board uses multi-level buffering to decouple communication and loop calculation, the data used for calculation in the current control cycle may come from several earlier cycles. Furthermore, when there are multiple forwarding or expansion modules between the driver board and the acquisition board, each relay may introduce a definite cycle-level delay. All of the above situations will cause the joint sensor data to have a fixed lag of more than two control cycles relative to the transmission time of the synchronization signal, thus making N a positive integer. However, as long as the lag is stably locked to a certain number of cycles under the action of the synchronization mechanism, the driver board can establish a reliable data and control cycle mapping relationship based on the corresponding N and complete the timing alignment.

[0096] 407. The drive board acquires the real-time rotational speed of the robot joints in the current control cycle, and calculates the change in angle and position of the joint sensor data during the transmission delay based on the real-time rotational speed and the duration corresponding to the fixed lag period N.

[0097] In this embodiment, in order to correct the historical state data after time alignment to real-time data that reflects the true state at the current moment, the driver board needs to perform dynamic compensation calculation based on the kinematic model.

[0098] First, the drive board acquires the real-time rotational speed of the robot joint within the current control cycle. This real-time rotational speed can be obtained by performing differential operations on continuously received joint position data, or estimated using a velocity observer algorithm set within the drive board; it represents the current mechanical motion rate of the joint. Subsequently, the drive board calculates the angular position change during the transmission delay based on this real-time rotational speed. Since the system's control cycle is extremely short, and the fixed lag period N determined in this embodiment is typically small, this time span, within the microseconds corresponding to N control cycles, is extremely short compared to the mechanical time constant of the motor rotor. Based on the principle of inertia, it can be approximated that the motor's mechanical speed remains constant within this tiny time slice, without drastic acceleration or deceleration changes. Based on the aforementioned short-term uniform velocity physical model, the drive board first calculates the total lag time corresponding to the fixed lag period N, and multiplies the real-time rotational speed by the total lag time to obtain the theoretical angle the joint rotor has rotated during the data transmission and processing period. This calculated product is the angular position change, used to characterize the cumulative displacement change of the joint from the completion of historical state data acquisition to the current control cycle.

[0099] 408. The drive board superimposes the change in angle position onto the position information in the historical state data to obtain the estimated joint position value for the current control cycle, and generates motor drive commands based on the estimated joint position value.

[0100] In this embodiment, the drive board performs the final position compensation calculation to reconstruct the joint motion state at the current moment. Specifically, the drive board algebraically superimposes the angular position change calculated in step 407 with the original position values ​​contained in the historical state data marked in step 406. Through superposition processing, the drive board numerically infers the sensor feedback data, which originally lagged behind the current physical time, to the moment of the current control cycle, thereby obtaining the joint position estimate for the current control cycle. In this way, the drive board compensates for the position information delay caused by the fixed transmission lag without changing the physical data transmission path, making the obtained joint position estimate closer to the actual motion state of the joint within the current control cycle.

[0101] Subsequently, the drive board inputs the timing-corrected and numerically compensated joint position estimate into its internal closed-loop control algorithm, such as the FOC vector control algorithm or the PID position loop control algorithm. Based on this estimate, the control algorithm calculates the required adjustment and generates corresponding motor drive commands, driving the motor to run along the target trajectory or control objective within the current control cycle. Compared to directly using uncompensated historical position data, this embodiment introduces the superposition processing of angular position changes, enabling the drive board to obtain continuous, smooth, and timing-consistent joint position inputs even with an external architecture and fixed communication lag. This effectively reduces position errors and control jitter caused by data delays, improving the overall control accuracy and dynamic response performance of the system.

[0102] In some specific embodiments, although the data transmission timing between the driver board and the intermediate signal processing unit is locked to a fixed lag period N through a synchronization signal mechanism, in actual long-term operating environments, factors such as temperature drift, power supply disturbances, or device aging may still affect the overall timing characteristics of the system, causing them to change slowly. Therefore, the driver board can monitor and adaptively correct the applicability of the fixed lag period N in real time during operation. Specifically, within each control cycle, the driver board records the transmission time of the synchronization signal while sending it, and records the actual reception time of the corresponding frame of joint sensor data upon receiving it. By comparing these two times, the driver board can obtain the actual transmission time difference of the joint sensor data in real time. Simultaneously, based on the currently used fixed lag period N and the control cycle length, the driver board can calculate the theoretically corresponding time difference. The driver board compares the actual time difference with the theoretical time difference; when the deviation exceeds a preset threshold, it is determined that the current fixed lag period N can no longer accurately represent the true timing relationship of the system. At this point, the driver board no longer uses the original fixed lag period number N. Instead, based on the latest monitored actual time difference, it recalculates the true lag period number of the joint sensor data relative to the synchronization signal and stores and uses the updated lag period number as the new fixed lag period number N. Subsequently, in subsequent control cycles, the driver board will re-label and time-map the received joint sensor data based on the updated fixed lag period number N, thereby ensuring that the correspondence between the data and the control cycle remains accurate and consistent.

[0103] It should be noted that, to achieve stable and reliable timing synchronization between the driver board and the acquisition board, the synchronization signal channel and the data communication channel can be configured differently in their physical implementation. In one implementation, the synchronization signal channel and the data communication channel are set up independently, with each channel carrying the synchronization signal and joint sensor data, respectively. Both the synchronization signal channel and the data communication channel use differential signal transmission to improve anti-interference capabilities in the complex electromagnetic environment inside the robot joint. Through differential transmission, the synchronization signal can maintain clear trigger edge characteristics even under conditions of long cables and strong motor interference, thus ensuring that the acquisition board can accurately identify the start time of each control cycle; at the same time, the data communication channel can also stably carry joint sensor data under high-frequency transmission conditions, avoiding bit errors or jitter caused by common-mode noise.

[0104] In another implementation, to further reduce the number of connections between the driver board and the acquisition board, the synchronization signal channel and the data communication channel can also reuse the same set of physical lines. In this implementation, the driver board still operates based on a preset control cycle and sends a synchronization signal to the acquisition board at the beginning of each control cycle. This synchronization signal is achieved by multiplexing the timing or protocol of existing communication lines. For example, the driver board can use time-division multiplexing to occupy the physical line and send a signal sequence with clear synchronization semantics within the starting time window of each control cycle; alternatively, the driver board can embed a synchronization identifier in the frame header of a regular data communication frame, enabling the acquisition board to simultaneously receive data and identify the synchronization signal when parsing the communication frame. Under the above multiplexing implementation, after receiving the time-division signal or synchronization identifier corresponding to the synchronization signal, the acquisition board can also identify it as the alignment reference for the control cycle and trigger the internal clock count to reset and the data acquisition to interrupt operation accordingly. In this way, the synchronization signal and data communication remain logically and functionally independent, while sharing of line resources is achieved at the physical level, thus ensuring timing consistency between the driver board and the acquisition board without increasing cable complexity.

[0105] The following provides a detailed description of the externally mounted robot joint drive board control system provided in this application. Please refer to [link / reference]. Figure 7 , Figure 7 Another embodiment of the robot joint drive board external control system provided in this application includes a drive board 701 disposed outside the robot joint and a data acquisition board 702 disposed on the side of the joint. The drive board 701 and the data acquisition board 702 are connected by a power line and a ground line. The drive board 701 supplies power to the data acquisition board 702 through the power line. A data communication channel and a synchronization signal channel are provided between the drive board 701 and the data acquisition board 702. The power line, the ground line and the signal transmission lines constituting the data communication channel and the synchronization signal channel are integrated into the same composite cable.

[0106] The driver board 701 is used to operate based on a preset control cycle, and sends a synchronization signal to the acquisition board 702 through a synchronization signal channel at the beginning of each control cycle.

[0107] The acquisition board 702 is used to perform a clock synchronization operation in response to receiving a synchronization signal, so as to calibrate the internal working timing of the acquisition board 702;

[0108] The acquisition board 702 is also used to acquire joint sensor data after performing clock synchronization operation, and send the joint sensor data to the driver board 701 through the data communication channel;

[0109] The driver board 701 is also used to receive joint sensor data, and based on the timing correspondence between the transmission time of the synchronization signal and the reception time of the joint sensor data, to perform timing alignment processing on the joint sensor data and complete joint control calculations.

[0110] In this embodiment, the functions of each unit are the same as described above. Figure 3 or Figure 4 The steps in the method embodiments shown correspond to those in the examples, and will not be repeated here.

[0111] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0112] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of 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 system, 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 apparatuses or units, and may be electrical, mechanical, or other forms.

[0113] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0114] Furthermore, the functional units in the various embodiments of this application 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.

[0115] 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 computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) 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.

Claims

1. A control method for an externally mounted robot joint drive plate, characterized in that, The robot includes a drive board disposed outside the joint and a data acquisition board disposed on the side of the joint. The drive board and the data acquisition board are connected by a power line and a ground line. The drive board supplies power to the data acquisition board through the power line. A data communication channel and a synchronization signal channel are provided between the drive board and the data acquisition board. The power line, the ground line, and the signal transmission lines constituting the data communication channel and the synchronization signal channel are integrated into the same composite cable. The control method includes: The acquisition board adopts a periodic pipeline-style communication strategy, which reads the data that has been communicated in the previous cycle within the current control cycle, and initiates a new round of data acquisition requests at the same time. The driver board operates based on a preset control cycle, and sends a synchronization signal to the acquisition board through the synchronization signal channel at the beginning of each control cycle. In response to receiving the synchronization signal, the acquisition board performs a clock synchronization operation to calibrate the internal working timing of the acquisition board; After performing the clock synchronization operation, the acquisition board acquires joint sensor data and sends the joint sensor data to the driver board through the data communication channel. The driver board acquires a pre-configured fixed hysteresis period number N, which is used to characterize the timing lag of the joint sensor data reception time relative to the synchronization signal transmission time. The drive board marks the received joint sensor data as historical state data of the Nth cycle before the current control cycle according to the fixed hysteresis cycle number N, thereby establishing a time mapping between the joint sensor data and the current control cycle, so as to complete the timing alignment of the joint sensor data and the control cycle, and complete the joint control calculation. The completion of joint control calculations includes: The drive board acquires the real-time rotational speed of the robot joint within the current control cycle, and calculates the angular position change of the joint sensor data during the transmission delay based on the real-time rotational speed and the duration corresponding to the fixed lag period N. The drive board superimposes the change in angle position onto the position information in the historical state data to obtain the estimated joint position value for the current control cycle, and generates motor drive commands based on the estimated joint position value.

2. The method according to claim 1, characterized in that, In response to receiving the synchronization signal, the acquisition board performs a clock synchronization operation, including: The acquisition board monitors the synchronization signal channel; When the trigger edge of the synchronization signal is detected, the acquisition board clears the internal timer counter and immediately triggers the data acquisition process corresponding to the current control cycle. The data collected from the joint sensors includes: In the data acquisition process, the acquisition board sets the trigger time of the synchronization signal as the start time of the data sampling period, and performs the acquisition operation of joint sensor data within the data sampling period to eliminate the phase drift between the acquisition board and the drive board.

3. The method according to claim 2, characterized in that, The control method further includes: When the acquisition board does not detect the trigger edge of the synchronization signal within the current control cycle, the acquisition board continues to execute the data acquisition process based on the internal working timing calibrated after the previous effective control cycle.

4. The method according to claim 1, characterized in that, The control method further includes: During operation, the drive board monitors in real time the time difference between the actual reception time of the joint sensor data and the transmission time of the synchronization signal. When the deviation between the time difference and the theoretical time difference corresponding to the fixed lag period number N exceeds a preset threshold, the drive board recalculates and updates the fixed lag period number N based on the current time difference.

5. The method according to claim 1, characterized in that, The synchronization signal channel and the data communication channel are set up independently of each other, and both adopt differential signal transmission.

6. The method according to claim 1, characterized in that, The synchronization signal channel and the data communication channel share the same set of physical lines; The driver board operates based on a preset control cycle, and at the beginning of each control cycle, it sends a synchronization signal to the acquisition board through the synchronization signal channel, including: The driver board operates based on a preset control cycle, and at the beginning of each control cycle, it sends a synchronization signal to the acquisition board on the physical line by time-division multiplexing or by embedding a synchronization identifier in the communication frame header.

7. The method according to any one of claims 1 to 6, characterized in that, The acquisition board is connected to a sensor group, which includes at least one of a motor-end encoder, a reducer-end encoder, a thermistor, and a torque sensor. After performing the clock synchronization operation, the acquisition board acquires joint sensor data, including: After performing the clock synchronization operation, the acquisition board synchronously reads the signal values ​​of each sensor in the sensor group through the onboard interface, and performs unified formatting processing on the read signal values.

8. A control system with an externally mounted robot joint drive plate, characterized in that, The control system includes a drive board disposed outside the robot joint and a data acquisition board disposed on the side of the joint. The drive board and the data acquisition board are connected by a power line and a ground line. The drive board supplies power to the data acquisition board through the power line. A data communication channel and a synchronization signal channel are provided between the drive board and the data acquisition board. The power line, the ground line, and the signal transmission lines constituting the data communication channel and the synchronization signal channel are integrated into the same composite cable. The acquisition board is used to adopt a periodic pipeline-style communication strategy to read the data that has been communicated in the previous cycle within the current control cycle, and at the same time initiate a new round of data acquisition requests. The drive board is used to operate based on a preset control cycle, and sends a synchronization signal to the acquisition board through the synchronization signal channel at the beginning of each control cycle. The acquisition board is used to perform a clock synchronization operation in response to receiving the synchronization signal, so as to calibrate the internal working timing of the acquisition board; The acquisition board is also used to acquire joint sensor data after performing the clock synchronization operation, and send the joint sensor data to the driver board through the data communication channel; The driver board acquires a pre-configured fixed hysteresis period number N, which is used to characterize the timing lag of the joint sensor data reception time relative to the synchronization signal transmission time. The drive board marks the received joint sensor data as historical state data of the Nth cycle before the current control cycle according to the fixed hysteresis cycle number N, thereby establishing a time mapping between the joint sensor data and the current control cycle, so as to complete the timing alignment of the joint sensor data and the control cycle, and complete the joint control calculation. The completion of joint control calculations includes: The drive board acquires the real-time rotational speed of the robot joint within the current control cycle, and calculates the angular position change of the joint sensor data during the transmission delay based on the real-time rotational speed and the duration corresponding to the fixed lag period N. The drive board superimposes the change in angle position onto the position information in the historical state data to obtain the estimated joint position value for the current control cycle, and generates motor drive commands based on the estimated joint position value.

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