Dual-motor synchronous control system and method for lifting pull basket

Abstract

The invention belongs to the technical field of pull baskets, and particularly relates to a dual-motor synchronous control system and method for a lifting pull basket. The system comprises a control module, a master execution module and a slave execution module, and a cooperative control closed loop of master motor active planning execution-slave motor real-time dynamic following is constructed. The track planning unit generates a control instruction according to the lifting instruction to drive a main motor; the first encoder collects the speed of the main motor in real time and feeds back the speed to the synchronous control unit; the synchronous control unit dynamically calculates a synchronous instruction enabling the real-time speed of the slave motor and the real-time speed of the master motor to be kept consistent according to the real-time speed feedback and planning instruction, and therefore the slave motor is driven to achieve accurate following. According to the invention, the synchronous basis is directly obtained from the motion source, so that the problem of insufficient synchronous precision of the double motors under the working condition of unbalanced load is solved, high-precision and high-dynamic synchronous lifting is realized, inclination, clamping stagnation and impact during operation are effectively avoided, the stability and safety of the system are improved, and the service life of the system is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of pull-out basket technology, specifically a dual-motor synchronous control system and method for raising and lowering pull-out baskets. Background Technology

[0002] With the increasing demand for kitchen storage, electric pull-out baskets have become an important functional component of modern kitchens. To meet diverse storage needs, pull-out baskets are becoming increasingly complex in form, often employing asymmetrical designs. For example, one side may be a lightweight multi-layered pull-out basket, while the other side integrates refrigeration, heating, and other functional cabinets, resulting in a significant difference in load capacity on both sides of the basket.

[0003] In such asymmetrical load conditions, achieving synchronous lifting and lowering operation of dual motors becomes a key challenge. Currently, most common dual-motor drive solutions employ open-loop synchronization or simple master-slave control strategies. Open-loop synchronization sends the same control commands to both motors, but due to motor characteristics, transmission resistance, and differences in load inertia on both sides, position and speed deviations are easily generated during actual operation. These deviations accumulate gradually, causing the basket to tilt and jam during lifting and lowering, and long-term operation may lead to mechanical wear and component failure. Although some solutions introduce master-slave control based on encoder feedback, they still mainly rely on fixed control parameters, resulting in limited dynamic response capabilities and difficulty in achieving stable, continuous, and high-precision synchronization under unbalanced load conditions.

[0004] Therefore, for lifting applications with asymmetrical loads, existing dual-motor control schemes still have shortcomings in achieving stable and reliable basic synchronous operation. There is an urgent need for a control method and system that can effectively cope with load differences and improve the synchronization accuracy of dual motors. Summary of the Invention

[0005] The first objective of this invention is to provide a dual-motor synchronous control system and method for lifting baskets, in order to solve the problem of insufficient stability of dual-motor synchronous control in the prior art when the load on both sides of the lifting basket is unbalanced.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A dual-motor synchronous control system for lifting and lowering a basket includes a control module, a main execution module, and a slave execution module. The control module includes a trajectory planning unit and a synchronization control unit. The main execution module includes a main motor, a main driver connected to the main motor, and a first encoder connected to the main motor to detect its operating speed. The slave execution module includes a slave motor and a slave driver connected to the slave motor. The trajectory planning unit is communicatively connected to the main driver to generate control commands based on lifting and lowering commands and outputs the control commands to the main driver. The first encoder is communicatively connected to the synchronization control unit to generate a speed feedback signal for the main motor. The synchronization control unit is communicatively connected to both the trajectory planning unit and the first encoder to generate synchronization commands based on the control commands and the speed feedback signal, and outputs the synchronization commands to the slave driver. The main driver drives the main motor according to the control commands, and the slave driver drives the slave motor according to the synchronization commands.

[0007] This invention provides a dual-motor synchronous control system based on dynamic real-time feedback and intelligent master-slave following. A trajectory planning unit generates smooth control commands (preferably S-curve speed planning) to drive the master motor. Simultaneously, a first encoder collects the actual speed of the master motor in real time as feedback. The synchronization control unit does not simply copy the commands; instead, based on the real-time speed feedback and the planned commands, it dynamically calculates synchronization commands that keep the slave motor's speed consistent with the master motor's, driving the slave motor to achieve precise following. This establishes a collaborative control closed loop of "master motor actively planning and executing – slave motor dynamically following in real time." Compared to existing technologies, this invention changes the fixed command or delayed response mode of traditional dual-motor control. It can directly obtain synchronization data from the motion source (the actual state of the master motor), achieving high-precision, high-dynamic synchronous lifting under conditions of uneven load on both sides of the lifting basket. This effectively avoids tilting, jamming, and impact caused by asynchrony, significantly improving operational stability, safety, and mechanism lifespan.

[0008] Furthermore, the main execution module also includes a main lifting mechanism, through which the main motor drives one side of the left and right sides of the lifting basket; the slave execution module also includes a slave lifting mechanism, through which the slave motor drives the other side of the left and right sides of the lifting basket. This design provides a direct and independent physical execution end for the synchronous control system of the present invention. By converting the rotational torque output by the main and slave motors into linear lifting forces via independent main and slave lifting mechanisms, and directly applying them to the corresponding sides of the lifting basket, the decoupling and distribution of driving forces are achieved.

[0009] Furthermore, the trajectory planning unit generates a smooth speed plan following the S-curve acceleration law, which serves as the control command. This design addresses the mechanical shock issues during the start-up, shutdown, and speed change processes of the lifting system. S-curve planning constrains the rate of acceleration change, ensuring a smooth and continuous transition in acceleration, resulting in an S-shaped speed curve. Compared to traditional trapezoidal speed planning, this method eliminates abrupt acceleration changes at the source, effectively reducing inertial shocks and mechanical vibrations during motion. This lays the kinematic foundation for the smooth operation of the main motor, making its speed output more stable and predictable, thereby reducing the disturbances and tracking difficulties faced by the slave motor during dynamic following.

[0010] Furthermore, the smooth speed planning includes the desired operating state of the slave motor; the control module also includes an online replanning unit and a replanning trigger unit; the replanning trigger unit monitors the actual operating state of the system and starts the online replanning unit when the preset replanning conditions are met; the online replanning unit is configured to regenerate the smooth speed plan from the actual operating state after startup, and update the control instructions and the synchronization instructions according to the updated smooth speed plan; the preset replanning conditions include at least one of the following: the load change of the lifting basket exceeds a first threshold; the error between the actual operating state and the desired operating state of the slave motor exceeds a second threshold. While the system operates according to the preset smooth speed plan, the replanning trigger unit monitors key states (such as load, and the error between the actual and desired states) in real time. Once a drastic load change or a synchronization error exceeding a safe range is detected, it is determined that the initial plan is no longer applicable to the current operating conditions, and the online replanning unit is immediately started. This unit does not simply stop and then restart, but rather uses the current real-time state of the system (such as speed and position) as a new starting point to quickly recalculate a smooth speed plan to the target position. This new planning inherits the smoothness of the S-curve and naturally incorporates the updated desired state of the slave motor. Subsequently, based on this new planning, the system simultaneously updates the control commands sent to the master motor and the desired reference for calculating the synchronization commands for the slave motor. This means that the master and slave motors will smoothly switch to an optimal trajectory that better reflects the current situation during operation, thereby achieving proactive suppression of sudden disturbances and online correction of errors. This mechanism empowers the system to move from "passively executing fixed plans" to "actively adapting to dynamic changes," significantly improving control robustness and reliability under complex and uncertain load conditions. It should be noted that the "desired operating state of the slave motor" mentioned in this application refers to the desired speed or desired position of the slave motor at any given time. This state is not set independently but is determined by the smooth speed planning of the master motor generated by the trajectory planning unit, based on the synchronization control objective of enabling the slave motor to follow the master motor in real time.

[0011] Furthermore, the synchronization control unit includes a feedforward controller and a feedback controller. The feedforward controller calculates a feedforward component based on the control command and the speed feedback signal. The feedback controller calculates a feedback component based on the error between the actual operating state and the desired operating state of the slave motor. The synchronization command is synthesized through the feedforward component and the feedback component. In this scheme, the feedforward controller calculates the feedforward component based on the control command and the speed feedback signal. By using known planning information and the real-time state of the master motor, it predicts and compensates for the ideal following action of the slave motor in advance, thereby reducing tracking delay and improving response speed. The feedback controller calculates the feedback component based on the real-time error between the actual operating state and the desired operating state of the slave motor. This feedback component is used to correct synchronization deviations caused by model bias, external disturbances, and feedforward residues in real time, ensuring long-term operational accuracy. Finally, the synchronization command is synthesized from the feedforward component and the feedback component. The combination of the two enables the slave motor to respond quickly to the dynamic changes of the master motor while maintaining high-precision synchronization.

[0012] Furthermore, the system also includes a safety monitoring module; the safety monitoring module includes a current sampling unit and an overload protection unit; the current sampling unit is connected in series in the power supply circuits of the main motor and the slave motor to collect the motor operating current signal; the overload protection unit is connected to the current sampling unit and the control module to output a protection signal to the control module when the motor operating current signal exceeds a preset threshold. In this scheme, the current sampling unit is connected in series in the motor power supply circuit to directly collect the operating current signal flowing through the motor, which directly reflects the actual load and operating status of the motor. The overload protection unit continuously compares the current signal with a preset current threshold, and once it detects that the current abnormally exceeds the threshold (such as due to stall, mechanical jamming, or severe overload), it quickly outputs a protection signal to the control module. This mechanism, as a hardware safety loop independent of the core control algorithm, can trigger an emergency shutdown or take protective measures before or after the software control response, thereby effectively preventing motor burnout, driver damage, or other cascading failures caused by excessive current, and improving the reliability and safety of the entire system under abnormal operating conditions.

[0013] Furthermore, the trajectory planning unit is configured to dynamically adjust the acceleration parameters in the smooth speed planning based on the real-time estimated load of the lifting basket. In this scheme, the system estimates the total load or load distribution on both sides of the lifting basket in real time through current and torque observation or state estimation algorithms. Based on this real-time load information, the trajectory planning unit dynamically adjusts the key parameters in its generated smooth speed planning—especially the maximum allowable acceleration. Specifically, when a light load or no load is detected, a higher acceleration value is used, enabling the system to respond to commands faster, shorten the running time, and improve overall efficiency and responsiveness; when a heavy load or excessive load is detected, a more conservative and lower acceleration value is switched to ensure sufficient motor output torque and avoid motor overload, loss of synchronization, or excessive inertial impact due to excessively high acceleration settings, thereby prioritizing the smoothness and safety of the lifting process.

[0014] Furthermore, the control module is configured to automatically tune the control parameters of the feedback controller based on the frequency domain characteristics of the error between the actual operating state and the desired operating state of the motor. In this scheme, the system continuously acquires the synchronization error signal and performs frequency domain analysis (such as Fourier transform or power spectral density estimation) on it to identify the dominant frequency components and their energy distribution in the error. For example, the analysis may find that the error energy is concentrated in a specific low-frequency band (suggesting a steady-state deviation or slow drift), or appears in a mid-to-high frequency band (possibly corresponding to mechanical resonance or periodic disturbance). Based on this frequency domain characteristic diagnosis result, the control module initiates a parameter self-tuning process. For example, if the error mainly manifests as low-frequency hysteresis, the integral gain of the feedback controller may be automatically increased to enhance the system's ability to eliminate steady-state errors; if the error exhibits oscillations at a specific frequency, the differential gain may be automatically adjusted or the parameters of the notch filter may be introduced to suppress resonance peaks and increase system damping. Through this online parameter self-tuning based on frequency domain error analysis, the feedback controller can autonomously match its control parameters (such as PID parameters) with the dynamic characteristics of the current actual mechanical system. This gives the system a certain degree of self-adaptability, enabling it to automatically maintain excellent control performance and synchronization accuracy during long-term operation or when facing slowly changing working conditions, thereby improving the system's robustness and maintenance-free nature.

[0015] Furthermore, the online replanning unit is configured to: smoothly switch the master motor and slave motor from their current motion state to the motion state defined by the newly generated smooth velocity plan through trajectory stitching and a gradual-in / gradual-out strategy. In this scheme, trajectory stitching is first performed, precisely calculating the connection points between the old and new trajectories in terms of position, velocity, and acceleration to ensure the kinematic state remains continuous and consistent at the moment of switching, avoiding shocks caused by state jumps; subsequently, a gradual-in / gradual-out strategy is adopted, weighting and fusing control commands during the transition period, gradually reducing the weight of the old trajectory and increasing the weight of the new plan to achieve a smooth transition of commands. This mechanism ensures that the online replanning process is shock-free and jitter-free, maintaining the continuity and stability of system operation throughout the process while dynamically adjusting the path.

[0016] Furthermore, the control module also includes an effect verification unit, which is configured to monitor system performance indicators after the online replanning unit updates the control instructions; if the performance indicators do not meet expectations, a secondary replanning is triggered or a rollback operation is performed to restore the control instructions before the update. In this scheme, when the online replanning unit updates the control instructions, the effect verification unit is immediately started, monitoring key system performance indicators (such as synchronization error and current stability) within a set time, and comparing and evaluating them in real time with the expected performance during replanning. If the performance meets or exceeds expectations, the verification is successful; if the performance does not meet expectations (such as increased error or oscillation), subsequent safety decisions are immediately triggered: either a secondary replanning is triggered to try a new strategy, or a rollback operation is performed to control the master and slave motors to safely return to the known stable instruction state before replanning. Through the closed loop of "planning-execution-verification-decision," this unit ensures that the system has self-evaluation and error correction capabilities while dynamically adapting to changes, thereby improving the overall robustness and safety of the intelligent control system.

[0017] Another objective of this invention is to provide a control method based on the control system described above, comprising the following steps: receiving a lifting command; generating a control command based on the lifting command and outputting the control command to a main driver to drive a main motor; acquiring a speed feedback signal of the main motor in real time; generating a synchronization command based on the control command and the speed feedback signal; and outputting the synchronization command to a slave driver to drive a slave motor, so that the running speed of the slave motor follows the real-time running speed of the main motor. The method of this invention has a closed-loop control logic of "planning-sensing-dynamic generation": firstly, a planned control command is generated based on the lifting command to drive the main motor. Crucially, while driving the main motor, the system continuously acquires the speed feedback signal of the main motor and uses it as one of the core bases for generating the drive command for the slave motor. Subsequently, the synchronization command is not a direct copy of the control command, but is dynamically calculated and generated based on the control command and the speed feedback signal. This allows the control signal of the slave motor to respond in real time to the actual movement changes of the main motor. Compared with the prior art, this invention, by applying the above-described control system, transforms the functionality of the hardware architecture into explicit timing steps. Therefore, dynamic closed-loop regulation can be achieved during operation through a streamlined sequence of receiving-generating-acquiring-regenerating-outputting instructions. This effectively overcomes tracking errors caused by load imbalance or disturbances, ensuring that the running speed of the slave motor follows the real-time running speed of the master motor, and guaranteeing high-precision synchronous lifting from the execution process. Attached Figure Description

[0019] Figure 1 This is the principle of the invention. Figure 1 ; Figure 2 This is a system block diagram of the present invention; Figure 3 This is the principle of the invention. Figure 2 ; Figure 4 This is the principle of the invention. Figure 3 ; Figure 5 This is a flowchart of the present invention. Detailed Implementation

[0021] The technical solution of the present invention will be further described below with reference to the accompanying drawings: Example 1: See Figure 1-3This embodiment discloses a dual-motor synchronous control system for lifting and lowering a basket, including a control module, a main execution module, and a slave execution module. The control module includes a trajectory planning unit and a synchronization control unit. The main execution module includes a main motor, a main driver connected to the main motor, and a first encoder connected to the main motor to detect its operating speed. The slave execution module includes a slave motor and a slave driver connected to the slave motor. The trajectory planning unit is communicatively connected to the main driver to generate control commands based on lifting and lowering commands and outputs the control commands to the main driver. The first encoder is communicatively connected to the synchronization control unit to generate a speed feedback signal for the main motor. The synchronization control unit is communicatively connected to both the trajectory planning unit and the first encoder to generate synchronization commands based on the control commands and the speed feedback signals and outputs the synchronization commands to the slave driver. The main driver drives the main motor according to the control commands, and the slave driver drives the slave motor according to the synchronization commands.

[0022] As a preferred embodiment, the lifting basket includes a basket assembly and a function box assembly, wherein the load of the function box assembly is greater than the load of the basket assembly, and the slave motor is a brushless DC motor of the same model and specifications as the master motor.

[0023] As a preferred embodiment, the safety monitoring module further includes a limiting device, which is used to limit the starting and ending positions of the lifting mechanism to ensure that the operation does not exceed the mechanical limits.

[0024] As a preferred embodiment, the current sampling unit of the safety monitoring module specifically includes a sampling resistor connected in series in the motor circuit, and a general-purpose operational amplifier connected to the sampling resistor. The general-purpose operational amplifier is used to amplify the sampled current signal so that the control module can acquire it.

[0025] Furthermore, the main execution module also includes a main lifting mechanism, through which the main motor drives one side of the left and right sides of the lifting basket; the slave execution module also includes a slave lifting mechanism, through which the slave motor drives the other side of the left and right sides of the lifting basket; the main lifting mechanism and the slave lifting mechanism are one of a ball screw pair, a synchronous belt pulley mechanism, or a gear and rack mechanism. This design provides a direct and independent physical execution end for the synchronous control system of this embodiment. By converting the rotational torque output by the main and slave motors into linear lifting forces via independent main and slave lifting mechanisms, and directly applying them to the corresponding sides of the lifting basket, the decoupling and distribution of driving forces are achieved.

[0026] As a preferred embodiment, the MCU controller in the control module receives the user's up, stop, or down commands via the control panel and converts the commands into a precise target position.

[0027] Furthermore, the trajectory planning unit generates a smooth speed plan following the S-curve acceleration law, which serves as the control command. This design addresses the mechanical shock issues during the start-up, shutdown, and speed change processes of the lifting system. S-curve planning constrains the rate of acceleration change, ensuring a smooth and continuous transition in acceleration, resulting in an S-shaped speed curve. Compared to traditional trapezoidal speed planning, this method eliminates abrupt acceleration changes at the source, effectively reducing inertial shocks and mechanical vibrations during motion. This lays the kinematic foundation for the smooth operation of the main motor, making its speed output more stable and predictable, thereby reducing the disturbances and tracking difficulties faced by the slave motor during dynamic following.

[0028] As a preferred embodiment, the smooth speed planning generated by the trajectory planning unit specifically decomposes the entire motion process into seven stages: acceleration, uniform acceleration, deceleration, uniform speed, acceleration / deceleration, uniform deceleration, and deceleration / deceleration, and calculates the duration of each stage in real time based on the motion distance and the maximum allowable speed.

[0029] Furthermore, the smooth speed planning includes the desired operating state of the slave motor; the control module also includes an online replanning unit and a replanning trigger unit; the replanning trigger unit monitors the actual operating state of the system and starts the online replanning unit when the preset replanning conditions are met; the online replanning unit is configured to regenerate the smooth speed plan from the actual operating state after startup, and update the control instructions and the synchronization instructions according to the updated smooth speed plan; the preset replanning conditions include at least one of the following: the load change of the lifting basket exceeds a first threshold; the error between the actual operating state and the desired operating state of the slave motor exceeds a second threshold. While the system operates according to the preset smooth speed plan, the replanning trigger unit monitors key states (such as load, and the error between the actual and desired states) in real time. Once a drastic load change or a synchronization error exceeding a safe range is detected, it is determined that the initial plan is no longer applicable to the current operating conditions, and the online replanning unit is immediately started. This unit does not simply stop and then restart, but rather uses the current real-time state of the system (such as speed and position) as a new starting point to quickly recalculate a smooth speed plan to the target position. This new plan inherits the smooth characteristics of the S-curve and naturally incorporates the updated desired state of the slave motor. Subsequently, based on this new plan, the system simultaneously updates the control commands sent to the master motor and the desired baseline used to calculate the synchronization commands for the slave motor. This means that the master and slave motors will smoothly switch to an optimal trajectory that better reflects the current situation during operation, thereby achieving proactive suppression of sudden disturbances and online correction of errors. This mechanism endows the system with the ability to move from "passively executing fixed plans" to "actively adapting to dynamic changes," significantly improving control robustness and reliability under complex and uncertain load conditions.

[0030] As a preferred embodiment, the load change is predicted by analyzing the sudden change trend of the motor current signal, and when the change trend is detected, a transition algorithm is started (i.e., the online replanning unit is started or the trajectory smoothing transition algorithm is called) to smoothly adjust the motion parameters and avoid sudden speed changes.

[0031] As a preferred embodiment, the replanning triggering unit is also used to initiate synchronization recovery replanning and re-establish the coordination relationship between the master and slave motors when the system synchronization error exceeds the limit.

[0032] Furthermore, the synchronization control unit includes a feedforward controller and a feedback controller. The feedforward controller calculates a feedforward component based on the control command and the speed feedback signal. The feedback controller calculates a feedback component based on the error between the actual operating state and the desired operating state of the slave motor. The synchronization command is synthesized through the feedforward component and the feedback component. In this scheme, the feedforward controller calculates the feedforward component based on the control command and the speed feedback signal. By using known planning information and the real-time state of the master motor, it predicts and compensates for the ideal following action of the slave motor in advance, thereby reducing tracking delay and improving response speed. The feedback controller calculates the feedback component based on the real-time error between the actual operating state and the desired operating state of the slave motor. This feedback component is used to correct synchronization deviations caused by model bias, external disturbances, and feedforward residues in real time, ensuring long-term operational accuracy. Finally, the synchronization command is synthesized from the feedforward component and the feedback component. The combination of the two enables the slave motor to respond quickly to the dynamic changes of the master motor while maintaining high-precision synchronization.

[0033] As a preferred embodiment, the synchronous control adopts a position-velocity dual closed-loop structure. The position loop tracks the planned trajectory to generate speed commands, while the speed loop ensures accurate speed tracking and outputs torque commands.

[0034] Furthermore, the system also includes a safety monitoring module; the safety monitoring module includes a current sampling unit and an overload protection unit; the current sampling unit is connected in series in the power supply circuits of the main motor and the slave motor to collect the motor operating current signal; the overload protection unit is connected to the current sampling unit and the control module to output a protection signal to the control module when the motor operating current signal exceeds a preset threshold. In this scheme, the current sampling unit is connected in series in the motor power supply circuit to directly collect the operating current signal flowing through the motor, which directly reflects the actual load and operating status of the motor. The overload protection unit continuously compares the current signal with a preset current threshold, and once it detects that the current abnormally exceeds the threshold (such as due to stall, mechanical jamming, or severe overload), it quickly outputs a protection signal to the control module. This mechanism, as a hardware safety loop independent of the core control algorithm, can trigger an emergency shutdown or take protective measures before or after the software control response, thereby effectively preventing motor burnout, driver damage, or other cascading failures caused by excessive current, and improving the reliability and safety of the entire system under abnormal operating conditions.

[0035] Furthermore, the trajectory planning unit is configured to dynamically adjust the acceleration parameters in the smooth speed planning based on the real-time estimated load of the lifting basket. In this scheme, the system estimates the total load or load distribution on both sides of the lifting basket in real time through current and torque observation or state estimation algorithms. Based on this real-time load information, the trajectory planning unit dynamically adjusts the key parameters in its generated smooth speed planning—especially the maximum allowable acceleration. Specifically, when a light load or no load is detected, a higher acceleration value is used, enabling the system to respond to commands faster, shorten the running time, and improve overall efficiency and responsiveness; when a heavy load or excessive load is detected, a more conservative and lower acceleration value is switched to ensure sufficient motor output torque and avoid motor overload, loss of synchronization, or excessive inertial impact due to excessively high acceleration settings, thereby prioritizing the smoothness and safety of the lifting process.

[0036] As a preferred embodiment, when the overload protection unit outputs a protection signal, it directly controls the power module to disconnect from the system and performs a hardware emergency stop.

[0037] Furthermore, the synchronization control unit is configured to adjust the contribution weights of the feedforward controller and the feedback controller to the synchronization command according to the motion stage of the lifting basket; wherein the motion stage includes an acceleration stage, a constant speed stage, and a deceleration stage. This strategy aims to optimize the allocation of control resources to address the differences in dynamic characteristics of different motion stages, thereby achieving better overall synchronization performance and efficiency. Specifically: In the constant speed stage, the system motion state is relatively stable, and disturbances mainly come from steady-state friction or slight load changes. At this time, feedforward control can provide accurate predictive compensation based on stable speed commands and main motor feedback, and is the main force in maintaining synchronization. Therefore, the system increases the weight of feedforward control and reduces the gain of feedback control, which can fully utilize the efficiency of feedforward and avoid unnecessary adjustment noise introduced by the feedback loop in a stable state, which is beneficial for energy saving and reducing overshoot. In the acceleration and deceleration stages, the system is in a dynamic process, with continuous changes in speed and acceleration, and the influence of model uncertainty and inertial force is more significant. At this time, feedback control is crucial for real-time suppression of dynamic errors and resistance to disturbances. Therefore, the system significantly increases the weight or gain of feedback control, enabling it to quickly respond to and correct tracking errors caused by model bias or load changes, ensuring close synchronization even during dynamic processes. Through this phased variable weight control, the system achieves intelligent switching of control strategies: efficient and quiet feedforward is dominant in the steady phase, while robust and corrective feedback is dominant in the dynamic phase. This allows the synchronization control unit to more effectively address control challenges at different stages, thereby achieving unified optimization of dynamic performance and steady-state accuracy throughout the entire motion cycle.

[0038] Furthermore, the control module is configured to automatically tune the control parameters of the feedback controller based on the frequency domain characteristics of the error between the actual operating state and the desired operating state of the motor. In this scheme, the system continuously acquires the synchronization error signal and performs frequency domain analysis (such as Fourier transform or power spectral density estimation) on it to identify the dominant frequency components and their energy distribution in the error. For example, the analysis may find that the error energy is concentrated in a specific low-frequency band (suggesting a steady-state deviation or slow drift), or appears in a mid-to-high frequency band (possibly corresponding to mechanical resonance or periodic disturbance). Based on this frequency domain characteristic diagnosis result, the control module initiates a parameter self-tuning process. For example, if the error mainly manifests as low-frequency hysteresis, the integral gain of the feedback controller may be automatically increased to enhance the system's ability to eliminate steady-state errors; if the error exhibits oscillations at a specific frequency, the differential gain may be automatically adjusted or the parameters of the notch filter may be introduced to suppress resonance peaks and increase system damping. Through this online parameter self-tuning based on frequency domain error analysis, the feedback controller can autonomously match its control parameters (such as PID parameters) with the dynamic characteristics of the current actual mechanical system. This gives the system a certain degree of self-adaptability, enabling it to automatically maintain excellent control performance and synchronization accuracy during long-term operation or when facing slowly changing working conditions, thereby improving the system's robustness and maintenance-free nature.

[0039] Furthermore, the online replanning unit is configured to: smoothly switch the master motor and slave motor from their current motion state to the motion state defined by the newly generated smooth velocity plan through trajectory stitching and a gradual-in / gradual-out strategy. In this scheme, trajectory stitching is first performed, precisely calculating the connection points between the old and new trajectories in terms of position, velocity, and acceleration to ensure the kinematic state remains continuous and consistent at the moment of switching, avoiding shocks caused by state jumps; subsequently, a gradual-in / gradual-out strategy is adopted, weighting and fusing control commands during the transition period, gradually reducing the weight of the old trajectory and increasing the weight of the new plan to achieve a smooth transition of commands. This mechanism ensures that the online replanning process is shock-free and jitter-free, maintaining the continuity and stability of system operation throughout the process while dynamically adjusting the path.

[0040] As a preferred embodiment, the trajectory stitching ensures that the old and new trajectories are continuous in terms of position, velocity, and acceleration. The gradual in and out strategy specifically involves gradually reducing the weight of the original trajectory and increasing the weight of the new trajectory.

[0041] Furthermore, the control module also includes an effect verification unit, which is configured to monitor system performance indicators after the online replanning unit updates the control instructions; if the performance indicators do not meet expectations, a secondary replanning is triggered or a rollback operation is performed to restore the control instructions before the update. In this scheme, when the online replanning unit updates the control instructions, the effect verification unit is immediately started, monitoring key system performance indicators (such as synchronization error and current stability) within a set time, and comparing and evaluating them in real time with the expected performance during replanning. If the performance meets or exceeds expectations, the verification is successful; if the performance does not meet expectations (such as increased error or oscillation), subsequent safety decisions are immediately triggered: either a secondary replanning is triggered to try a new strategy, or a rollback operation is performed to control the master and slave motors to safely return to the known stable instruction state before replanning. Through the closed loop of "planning-execution-verification-decision," this unit ensures that the system has self-evaluation and error correction capabilities while dynamically adapting to changes, thereby improving the overall robustness and safety of the intelligent control system.

[0042] As a preferred embodiment, the rollback mechanism immediately restores the system to the previous valid plan when system instability is detected, the priority management mechanism is used to handle multiple triggering conditions, and the incremental replanning strategy is used to avoid drastic changes.

[0043] Furthermore, the synchronization control unit is also configured to filter the control command and the speed feedback signal when generating the synchronization command, so as to suppress mechanical resonance at a specific frequency.

[0044] As a preferred solution, the system incorporates mechanical resonance frequency data, filters out excitation frequency components in advance during the trajectory planning stage, and achieves real-time vibration monitoring and dynamic adjustment through feedback from acceleration sensors.

[0045] Furthermore, the control module stores a multi-dimensional parameter mapping table. This table is used to retrieve corresponding control parameters based on at least one of the following: the operating speed, load size, and temperature status of the lifting basket. The trajectory planning unit and the synchronization control unit use the control parameters retrieved from the table. In this scheme, the system establishes a parameter database indexed by key operating condition variables through pre-tuning. During actual operation, the current operating condition is monitored in real time, and the optimal set of control parameters (such as planning acceleration, control gain, etc.) is quickly retrieved using this index. For operating points not precisely covered, an interpolation algorithm is used to achieve smooth parameter transition. The trajectory planning unit and the synchronization control unit then apply these parameters, causing their output to automatically adapt to real-time changes in operating conditions. This mechanism enables the system to continuously and smoothly adjust control parameters automatically based on multi-dimensional conditions such as speed, load, and temperature, thereby maintaining near-optimal performance across the entire operating range and achieving high-performance adaptive control.

[0046] As a preferred approach, the system continuously learns the optimal parameters under different operating conditions and constantly optimizes and updates the multidimensional parameter mapping table.

[0047] This embodiment provides a dual-motor synchronous control system based on dynamic real-time feedback and intelligent master-slave following. A trajectory planning unit generates smooth control commands (preferably S-curve speed planning) to drive the master motor. Simultaneously, a first encoder collects the actual speed of the master motor in real time as feedback. The synchronization control unit does not simply copy the commands; instead, based on the real-time speed feedback and the planned commands, it dynamically calculates synchronization commands that keep the slave motor's speed consistent with the master motor's, driving the slave motor to achieve precise following. This constructs a collaborative control closed loop of "master motor actively planning and executing – slave motor dynamically following in real time." Compared with existing technologies, this embodiment changes the traditional dual-motor control mode of fixed commands or delayed response. It can directly obtain synchronization data from the motion source (the actual state of the master motor), achieving high-precision, high-dynamic synchronous lifting under conditions of uneven load on both sides of the lifting basket. This effectively avoids tilting, jamming, and impact caused by asynchrony, significantly improving operational stability, safety, and mechanism lifespan.

[0048] Example 2: See Figure 5 This embodiment discloses a control method based on the control system described above, and includes the following steps: receiving a lifting command; generating a control command based on the lifting command and outputting the control command to the main driver to drive the main motor to run; acquiring the speed feedback signal of the main motor in real time; generating a synchronization command based on the control command and the speed feedback signal; and outputting the synchronization command to the slave driver to drive the slave motor to run, so that the running speed of the slave motor follows the real-time running speed of the main motor.

[0049] As a preferred embodiment, the control command receives user operation instructions through the control panel, and then the MCU controller calculates and generates the target position.

[0050] Furthermore, the step of generating control commands includes: generating a smooth speed plan that follows the S-curve acceleration law based on the target position corresponding to the lifting command, as the control command; wherein the smooth speed plan includes the desired operating state of the slave motor; the control method further includes the following steps: monitoring the system status; if the load change of the lifting basket exceeds a first threshold, or the synchronization error between the actual operating state of the slave motor and the desired operating state exceeds a second threshold, then regenerating the smooth speed plan starting from the actual operating state, and updating the control command and synchronization command.

[0051] As a preferred embodiment, the load change is predicted by monitoring the trend of motor current change, and the motion parameters are adjusted smoothly in advance when a sudden change is predicted.

[0052] Furthermore, the steps for generating synchronization commands include: employing a feedforward-feedback composite control algorithm; calculating feedforward control components based on the control commands and the speed feedback signal; acquiring the actual operating state of the slave motor in real time and comparing it with the expected operating state based on the current control commands, calculating feedback control components through a PID controller; and synthesizing the feedforward control components and the feedback control components to generate the synchronization commands. This scheme provides the system with a stable and complete reference command by generating a smooth speed plan that includes S-curve patterns and the expected operating state; simultaneously, it sets monitoring and replanning trigger conditions based on load mutations and synchronization errors. When a drastic load change or an actual synchronization error exceeding the safe range is detected, it indicates that the initial plan has deviated from the optimal state. The system then uses the current actual motion state as a new starting point to recalculate the smooth speed plan and its embedded expected operating state, and updates the control commands and synchronization commands accordingly. This mechanism enables the control method to perceive changes in operating conditions and execution deviations online and actively adjust subsequent command sequences, thereby achieving an upgrade from "fixed program execution" to "dynamic adaptive optimization" at the method level, improving the ability to maintain high-precision synchronization continuously under uncertain load environments.

[0053] As a preferred embodiment, during the uniform speed motion phase of the main motor, the control mainly relies on the feedforward control component; during the acceleration and deceleration phases, the compensation effect of the feedback control component is strengthened.

[0054] Furthermore, it includes safety monitoring steps: real-time monitoring of the operating current of the main motor and the slave motor; triggering an emergency stop operation when the operating current exceeds a preset threshold.

[0055] As a preferred embodiment, the emergency stop operation includes disconnecting the power module from the motor system.

[0056] This embodiment features a closed-loop control logic of "planning-sensing-dynamic generation": First, a planned control command is generated based on the lifting command to drive the main motor. Crucially, while driving the main motor, the system continuously acquires the speed feedback signal of the main motor and uses it as one of the core bases for generating the drive command for the slave motor. Subsequently, the synchronization command is not a direct copy of the control command, but is dynamically calculated and generated based on the control command and the speed feedback signal. This allows the control signal of the slave motor to respond in real time to the actual movement changes of the main motor. Compared with existing technologies, this embodiment, by applying the aforementioned control system, transforms the functionality of the hardware architecture into explicit timing steps. Therefore, through a streamlined sequence of receiving-generating-acquiring-regenerating-output commands, dynamic closed-loop adjustment is achieved during operation. This effectively overcomes tracking errors caused by load imbalance or disturbances, ensuring that the running speed of the slave motor follows the real-time running speed of the main motor, thus guaranteeing high-precision synchronous lifting from the execution flow perspective.

[0057] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to this invention should also fall within the protection scope of the claims of this invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this invention.

Claims

1. A dual-motor synchronous control system for lifting baskets, characterized in that, The control system comprises: a control module comprising a trajectory planning unit and a synchronization control unit; a main execution module comprising a main motor, a main driver connected to the main motor, and a first encoder connected to the main motor to detect the running speed of the main motor; a slave execution module comprising a slave motor and a slave driver connected to the slave motor; the trajectory planning unit is connected in communication with the main driver to generate a control instruction according to a lifting instruction and output the control instruction to the main driver; the first encoder is connected in communication with the synchronization control unit to generate a speed feedback signal of the main motor; the synchronization control unit is connected in communication with the trajectory planning unit and the first encoder to generate a synchronization instruction according to the control instruction and the speed feedback signal and output the synchronization instruction to the slave driver; the main driver drives the main motor according to the control instruction, and the slave driver drives the slave motor according to the synchronization instruction.

2. The control system of claim 1, wherein, The main execution module further comprises a main lifting mechanism, and the main motor drives one side of the left and right sides of the lifting basket through the main lifting mechanism; the slave execution module further comprises a slave lifting mechanism, and the slave motor drives the other side of the left and right sides of the lifting basket through the slave lifting mechanism.

3. The control system of claim 2, wherein: The trajectory planning unit generates a smooth speed planning following an S-curve acceleration rule as the control instruction.

4. The control system according to claim 3, wherein: the smooth speed planning comprises a desired running state of the slave motor; the control module further comprises an online re-planning unit and a re-planning triggering unit; the re-planning triggering unit monitors an actual running state of the system and starts the online re-planning unit when a preset re-planning condition is met; the online re-planning unit is configured to regenerate a smooth speed planning with the actual running state as a starting point after being started, and update the control instruction and the synchronization instruction according to the updated smooth speed planning; the preset re-planning condition comprises at least one of the following: a load change amount of the lifting basket exceeds a first threshold value; an error between the actual running state and the desired running state of the slave motor exceeds a second threshold value.

5. The control system of claim 4, wherein: The synchronization control unit comprises a feedforward controller and a feedback controller; the feedforward controller calculates a feedforward component based on the control instruction and the speed feedback signal; the feedback controller calculates a feedback component based on an error between the actual running state and the desired running state of the slave motor; the synchronization instruction is synthesized by the feedforward component and the feedback component.

6. The control system of claim 1 or 4, wherein: The system further comprises a safety monitoring module; the safety monitoring module comprises a current sampling unit and an overload protection unit; the current sampling unit is connected in series in a power supply circuit of the main motor and the slave motor to collect a motor working current signal; the overload protection unit is connected to the current sampling unit and the control module to output a protection signal to the control module when the motor working current signal exceeds a preset threshold value.

7. The control system of claim 4, wherein: The online re-planning unit is further configured to control the master motor and the slave motor to smoothly switch from a current motion state to a motion state defined by the re-generated smooth velocity plan through trajectory stitching and fade-in and fade-out strategies.

8. The control system of claim 4, wherein: The control module further comprises an effect verification unit. The effect verification unit is configured to monitor system performance indicators after the online re-planning unit updates the control instructions, and if the performance indicators do not meet expectations, trigger a secondary re-planning or perform a rollback operation to restore to the control instructions before the update.

9. The control system of claim 5, wherein: The control module is further configured to automatically tune the control parameters of the feedback controller according to the frequency domain characteristics of the error between the actual operating state and the expected operating state of the slave motor.

10. A control method characterized by, It is based on the control system according to any one of claims 1-9, and comprises the following steps: receiving a lifting instruction; generating a control instruction according to the lifting instruction and outputting the control instruction to a master driver to drive the master motor to operate; obtaining a speed feedback signal in real time when the master motor operates; generating a synchronization instruction according to the control instruction and the speed feedback signal; outputting the synchronization instruction to a slave driver to drive the slave motor to operate, so that the operating speed of the slave motor follows the real-time operating speed of the master motor.

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