Synchronous control method of dual-drive motion system based on adaptive compensation of synchronization error

Abstract

The present invention relates to a synchronous control method for a dual-drive motion system based on adaptive compensation of synchronization error, and belongs to the field of intelligent manufacturing. First, an adaptive synchronization control system is designed, and a parallel synchronization control architecture is adopted to organize two single-axis speed tracking control loops and a synchronization error compensation control loop, including a speed-current cascade closed-loop controller, a tracking performance comparison switch, and a synchronization error compensator. Secondly, a real-time synchronization error selective compensation strategy is designed, and the tracking performance comparison switch is used to identify motors with weak tracking performance, and the synchronization speed error is converted into a current compensation signal of a current closed-loop controller through a synchronization error compensator. Finally, a single-axis tracking-dual-axis synchronization composite motion controller is designed, including a speed closed-loop controller using a sliding mode control method and a current closed-loop controller using a PID control method. The method of the present invention is conducive to the mutual promotion of the tracking performance of the two motors, and can take into account both single-axis tracking performance and dual-axis synchronous motion.

Description

Technical Field

[0001] The present invention relates to the field of intelligent manufacturing, and in particular to a synchronous control method for a dual-drive motion system based on adaptive compensation of synchronization errors. Background Art

[0002] Synchronous control is a key technology for achieving high-speed, high-precision positioning control in dual-drive motion systems. It improves the dynamic performance of drive motors and their robustness against nonlinear disturbances. It is often used in intelligent manufacturing applications such as automated production equipment, intelligent transportation, and mechanical positioning. Common synchronous control methods include parallel synchronous control, master-slave synchronous control, and cross-coupling control. Parallel synchronous control maintains synchronization by independently controlling the tracking accuracy of the two motors relative to a reference input. However, the lack of direct communication between the two motors results in poor synchronization performance. Master-slave synchronous control employs a series control scheme in which a reference signal is input to the master motor and its output is used as the input to the slave motor. However, this scheme can cause the actual output to deviate from the desired signal due to cumulative error transmission. Cross-coupling control compensates for synchronization errors in each motor when the two motors are controlled independently, potentially averaging the tracking performance of the two motors. However, it may prioritize motion synchronization between the two motors, weakening the original tracking performance of each motor. Summary of the Invention

[0003] In order to solve the limitations of the above three dual-drive motion system synchronization control methods, this paper invents a dual-drive motion system synchronization control method based on adaptive compensation of synchronization error. By innovatively designing a selective compensation strategy, the synchronization error is compensated in real time to the controller input end of the motor with weak tracking performance at the current moment, and the synchronization error is compensated in combination with the sliding mode controller, and the tracking error is feedback controlled. This can not only improve the synchronization of the two motors, but also ensure the tracking performance of each motor for its own target signal, which is beneficial to the high-speed and high-precision positioning control of the dual-drive motion system.

[0004] The present invention is achieved through the following technical solutions:

[0005] A synchronous control method for a dual-drive motion system based on adaptive compensation of synchronization error comprises the following steps:

[0006] Step 1: Adaptive synchronous control system design: First, design a parallel synchronous control architecture, using it to organize two single-axis speed tracking control loops and a synchronization error compensation control loop. Next, design a single-axis speed tracking control loop using a cascade closed-loop controller that combines speed closed-loop control with current closed-loop control. Finally, design a synchronization error compensation control loop, including a synchronization error calculation module, a tracking performance comparison switch, and a synchronization error compensator.

[0007] Step 2: Design a real-time synchronization error selective compensation strategy: First, design a tracking performance comparison switch to distinguish the two motors according to strong and weak tracking performance at each sampling cycle. Next, design a synchronization error calculation module to calculate the synchronization speed error by calculating the difference between the actual speed signals of the two motors. Finally, design a synchronization error compensator to convert the synchronization speed error into a current compensation signal for the current closed-loop controller for motors with weak tracking performance.

[0008] Step 3: Design of single-axis tracking-dual-axis synchronous composite motion controller: First, establish the dynamic model of the dual-drive motion system; secondly, design a single-axis tracking motion controller, and use the speed error signal as input for speed closed-loop control; thirdly, design a dual-axis synchronous motion controller, and use the current error signal as input for current closed-loop control, thereby completing the single-axis tracking-dual-axis synchronous composite motion control.

[0009] Furthermore, the adaptive synchronous control system design method comprises the following steps:

[0010] Step 1.1: Design a parallel synchronous control architecture: Use a parallel synchronous control architecture to organize two single-axis speed tracking control loops. These two control loops receive the same target speed signal input but operate independently. The outputs of the two single-axis speed tracking control loops are connected to the input of the synchronous error compensation control loop. The actual speed and actual position signals output by the two motors are processed by the synchronous error compensation control loop and then input into the single-axis speed tracking control loop as current compensation commands.

[0011] Step 1.2: Single-axis speed tracking control loop design: The single-axis speed tracking control loop uses a cascade closed-loop controller that combines speed closed-loop control with current closed-loop control. The control loop also includes a vector controller (Field-Oriented Controller, FOC), an inverter drive, and a linear motor. The target speed signal is input into the cascade closed-loop controller. The voltage signal processed by the controller is converted into a pulse signal by the vector controller, which controls the inverter drive to drive the linear motor. The actual current signal generated by the linear motor movement is fed back to the input of the current closed-loop controller, and the actual speed signal generated by the linear motor movement is fed back to the input of the speed closed-loop controller.

[0012] Step 1.3: Design of synchronous error compensation control loop: The synchronous error compensation control loop consists of a synchronous error calculation module, a tracking performance comparison switch and a synchronous error compensator; the actual speed signals generated by the movement of the two motors are processed into synchronous speed errors by the synchronous error calculation module, and the actual position signals generated by the movement of the two motors are processed by the tracking performance comparison switch (TPCS) to obtain a switch control signal, which controls the selective compensation switch of the synchronous speed error and outputs the synchronous speed error to the synchronous error compensator of the corresponding compensation object. After speed compensation processing, it is input into the current closed-loop controller input end of the single-axis speed tracking control loop of the corresponding compensation object in the form of current compensation instructions.

[0013] Furthermore, the real-time synchronization error selective compensation strategy design method comprises the following steps:

[0014] Step 2.1: Tracking performance comparison switch design: Design a tracking performance comparison switch for evaluating the tracking performance of two motors. The switch uses the absolute position error and mean square position error between the actual position signal of each motor and the target position signal as the judgment basis. As shown in formula (1), the two motors are distinguished as strong tracking performance and weak tracking performance at each sampling cycle: first, the absolute position errors of the two motors are judged, and the motor with the larger absolute position error is regarded as weak tracking performance; if the absolute position errors of the two motors are equal, the mean square position error is judged, and the motor with the larger mean square position error is regarded as weak tracking performance; if the absolute position errors and mean square position errors of the two motors are equal, one motor is randomly selected as weak tracking performance; and the switch control signal of the tracking performance comparison switch is determined with the motor with weak tracking performance as the compensation object;

[0015]

[0016] Among them, S ref is the target position signal, S i is the actual position signal of motor number i, e s is the absolute position error, MSE is the mean square position error, τ is the current time, and t is the running time;

[0017] Step 2.2: Synchronous error calculation module design: The synchronous error calculation module obtains the synchronous speed error E by calculating the difference between the actual speed signals of the two motors. v , the error is equal to the actual speed V of the motor for strong tracking performance 强 Subtract the actual speed V of the motor with weak tracking performance 弱 :

[0018] E v =V强 -V 弱 (2)

[0019] Step 2.3: Synchronous error compensator design: The synchronous error compensator is divided into speed compensator 1 and speed compensator 2 according to the motor number i. The synchronous speed error is input into the speed compensator of the corresponding compensation object through the tracking performance comparison switch, and then the speed compensation is processed by the sliding mode control method to generate the current compensation signal of the current closed-loop controller in the corresponding compensation object.

[0020] Furthermore, the design of the single-axis tracking-dual-axis synchronization composite motion controller includes the following steps:

[0021] Step 3.1: Modeling method of dual-drive motion system: First, establish the dynamic equation of the dual-drive motion system motor: as shown below:

[0022] F m =F a +F f +F d (3)

[0023] Among them, F m is the driving force, F a is the inertial force, F f is the viscous friction force, F d are other disturbance forces, which are ignored in the modeling stage;

[0024] The driving force model is established based on the voltage balance equation and magnetic flux model of the permanent magnet synchronous motor:

[0025]

[0026] Where C is the motor driving force constant, P n is the number of motor pole pairs, ψ f is the effective magnetic flux generated by the permanent magnet, σ is the pole pitch, and i is the driving current;

[0027] According to formulas (3) and (4), the dynamic model of the dual-drive motion system is established:

[0028]

[0029] Where B is the viscous friction coefficient, k is the motor number, m is the load mass, m k is the primary mass of the motor, s(t) is the function of the linear motor position signal with respect to time, and i(t) is the function of the linear motor current signal with respect to time;

[0030] Step 3.2: Design a single-axis tracking motion controller: The single-axis tracking motion controller is a speed closed-loop controller using a sliding mode control method. The controller input signal is the motor speed error signal, that is, the difference between the target speed signal and the actual speed signal. The controller calculates the current control command corresponding to the speed error signal using the sliding mode control method to achieve single-axis tracking motion control, and outputs the current control command to the input of the current closed-loop controller.

[0031] Step 3.3: Design of dual-axis synchronous motion controller: The dual-axis synchronous motion controller is a current closed-loop controller using the PID control method. It integrates the current control instruction of the single-axis tracking motion controller and the current compensation information of the synchronous error compensator as the control target of the current loop. The current error signal is calculated based on the actual current signal fed back by the inverter drive. The voltage control instruction corresponding to the current error signal is calculated through the PID control method to realize dual-axis synchronous motion control.

[0032] Further according to the sliding mode control method described in steps 2 and 3, the following steps are included:

[0033] Step 4.1: Sliding surface design: Design the sliding surface based on the motor dynamics model. First, set the state variables x1 and x2:

[0034]

[0035] Among them, v ref is the target speed signal, v is the actual speed signal, is the state quantity x1 after derivation;

[0036] Combining formula (6) with formula (5), the system state space equation is established:

[0037]

[0038] Wherein, the control input is u = i(t)′, and the mass of the load and the motor primary is M = m + m0;

[0039] Design sliding surface function based on system state space equation

[0040] s=cx1+x2 (8)

[0041] Among them, the design parameter c>0;

[0042] By differentiating formula (8), we can obtain the sliding surface derivative function:

[0043]

[0044] Step 4.2: Exponential approach rate design: Based on the sliding surface function and the system state space equation, design the exponential approach rate used in the sliding mode control method:

[0045]

[0046] Among them, the design parameters ε>0, q>0; sgn() is the sign function;

[0047] Step 4.3: Sliding mode controller design: First, substitute the exponential approach rate formula (10) into the sliding surface derivative function formula (9) to establish a preliminary sliding mode controller:

[0048]

[0049] Then, the control input u = i(t)′ is substituted into formula (11) to obtain the final sliding mode controller:

[0050]

[0051] Among them, i is the current control variable.

[0052] Compared with existing synchronous control technologies such as parallel synchronous control, master-slave synchronous control, and cross-coupling control, the present invention has at least the following beneficial effects or advantages:

[0053] (1) Compared with the parallel synchronous control method, the present invention overcomes the problem of poor synchronization when the two motors run independently.

[0054] (2) Compared with the master-slave synchronous control method, the present invention changes the traditional control mode in which the slave motor only tracks the motion state of the master motor and ignores the direct tracking of the target motion state, and overcomes the problem of the continuous increase of the slave motor target tracking error due to the accumulation of error transmission.

[0055] (3) Compared with the cross-coupling control method, the present invention changes the potential processing mechanism for averaging the strong and weak tracking performances of the two motors, which is beneficial to the mutual promotion of the tracking performances of the two motors, and improves the target tracking performance of each motor while ensuring the motion synchronization between the two motors. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The present invention will be described in further detail below with reference to the accompanying drawings:

[0057] Figure 1 A step diagram of a synchronous control method for a dual-drive motion system based on adaptive compensation of synchronization errors;

[0058] Figure 2 This is a diagram of the adaptive synchronization control architecture;

[0059] Figure 3 Flowchart of switches for tracking performance comparison;

[0060] Figure 4 This is the linear motor dynamic analysis diagram. DETAILED DESCRIPTION

[0061] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0062] The present invention provides a method for synchronous control of a dual-drive motion system based on adaptive compensation of synchronization errors, such as Figure 1 The method specifically includes the following steps:

[0063] Step 1: Design of adaptive synchronous control system: Figure 2 As shown in , a parallel synchronous control architecture is used to organize two single-axis speed tracking control loops and a synchronous error compensation control loop, and the single-axis speed tracking control loop and the synchronous error compensation control loop are designed separately.

[0064] The parallel synchronous control architecture controls two single-axis speed tracking control loops to run independently and in parallel under the same target speed input signal, but the dual-drive synchronization performance of this architecture is poor. Therefore, the design connects the two single-axis speed tracking control loops through a synchronous error compensation control loop, so that the adaptive synchronous control system takes into account both single-axis accuracy and dual-drive synchronization; the design of the single-axis speed tracking control loop adopts a cascade closed-loop controller that combines speed closed-loop control and current closed-loop control; the design of the synchronous error compensation control loop includes a synchronous error calculation module, a tracking performance comparison switch and a synchronous error compensator.

[0065] Step 1.1: Parallel synchronous control architecture design: Construct a parallel synchronous control architecture, give the same target input signal, and control the two single-axis speed tracking control loops to operate independently; the input target speed signal is converted into the actual speed signal and actual position signal output by the two motors through loop processing. The signal is processed by the synchronous error compensation control loop to generate a current compensation command that is input into the single-axis speed tracking control loop.

[0066] Step 1.2: Single-axis speed tracking control loop design: Use a cascade closed-loop controller combining the speed loop and the current loop to Figure 2 Target input speed signal V ref Perform calculations to generate a voltage control signal U q , the pulse signal PWM is obtained through the FOC algorithm, thereby controlling the inverter drive to drive the linear motor movement, where the actual three-phase current i output by the inverter is abcThe actual speed signals V1 and V2 output by the motor are fed back to the input of the speed loop controller to form a closed-loop control.

[0067] Step 1.3: Synchronous error compensation control loop design: The loop consists of three parts: synchronous error calculation module, tracking performance comparison switch (TPCS) and synchronous error compensator. The actual speed signals V1 and V2 generated by the two motors in the single-axis speed tracking control loop in step 1.1 are processed by the synchronous error calculation module to generate the synchronous speed error e. v1 ,e v2 The tracking performance comparison switch TPCS controls the conduction state of the synchronous speed error output route; TPCS processes the actual position output signals of the two motors and obtains the switch state parameter d. According to the parameter, the corresponding switch port 1 or 2 is opened, that is, Figure 2 The on and off states of switches 1 and 2 in the middle, only one of ports 1 and 2 can be turned on at the same time, the synchronous speed error is processed by the corresponding synchronous error compensator, and is input into the current loop controller input end of the single-axis speed tracking control loop of the corresponding compensation object in the form of current compensation instruction.

[0068] Step 2: Design method of real-time synchronization error selective compensation strategy: Design the algorithm of tracking performance comparison switch TPCS, stipulate that the strength of motor tracking performance is judged in each independent sampling cycle, and the judgment indicators are absolute position tracking error and mean square position error, so as to determine the compensation object; design a synchronization error calculation module to calculate the synchronous speed error value of the two motors; design a synchronization error compensator, and for motors with weak tracking performance, process the synchronous speed error value through the compensator operation into a current compensation feedforward signal of the current loop controller.

[0069] Step 2.1: Tracking performance comparison switch design: Figure 3 As shown in the figure, a tracking performance comparison switch TPCS is designed to evaluate the tracking performance of two motors. The judgment indicators of the switch are set as the absolute position error and mean square position error between the actual position signal and the target position signal of each motor. As shown in formula (1), a real-time judgment is performed in each sampling cycle. If the judgment indicator is large, the tracking performance is weak, and the corresponding motor is used as the compensation object of the current cycle. If the indicator is small, the tracking performance is strong.

[0070]

[0071] Among them, S ref is the target position signal, S i is the actual position signal of motor number i, e s is the absolute position error, MSE is the mean square position error, τ is the current time, and t is the running time.

[0072] First, determine indicator 1: the absolute position error e s , a motor with a small error indicates that the error between the target position and the actual position of the motor at the current moment is small, and the motor is regarded as having strong tracking performance, while the motor with weak tracking performance is regarded as the compensation object of the current cycle; if the absolute position error cannot be judged, that is, they are equal, then continue to compare the size of the mean square position error MSE to judge, the motor with a small mean square error is regarded as having strong tracking performance, while the motor with weak tracking performance is regarded as the compensation object of the current cycle; if the mean square error still cannot be judged, then motor 1 is defaulted to being a motor with weak tracking performance and the compensation object; the above method can determine the switch opening state, that is, the value of d. When the d value is 1, the compensation object is motor 1, and port 1 of the switch is turned on. When the d value is 2, the compensation object is motor 2, and port 2 of the switch is turned on.

[0073] Step 2.2: Synchronous error calculation module design: Design a synchronous error calculation module to calculate the difference between the actual speed signals of the two motors to obtain the synchronous speed error e v1 ,e v2 , the error value is equal to the actual speed V of the motor with strong tracking performance 强 Subtract the actual speed V of the motor with weak tracking performance 弱 , as shown in Formula 2.

[0074] E v =V 强 -V 弱 (2)

[0075] When motor 2 is a strong tracking performance motor and motor 1 is a weak tracking performance motor, then V 强 is the speed of motor 2, namely V2, V 弱 is the speed of motor 1, that is, V1. At this time, the synchronous speed error is E v =e v1 =V2-V1. When motor 1 is a strong tracking performance motor and motor 2 is a weak tracking performance motor, then V 强 is the speed of motor 1, namely V1, V 弱 is the speed of motor 2, that is, V2. At this time, the synchronous speed error is E v =e v2 =V1-V2.

[0076] Step 2.3: Synchronous error compensator design: The synchronous error compensator is divided into speed compensator 1 and speed compensator 2 according to the motor number i. The synchronous speed error is input into the speed compensator of the corresponding compensation object through the tracking performance comparison switch, and then the speed compensation is processed by the sliding mode control method to generate the current compensation signal of the current closed-loop controller in the corresponding compensation object.

[0077] When motor 2 is a strong tracking performance motor and motor 1 is a weak tracking performance motor, the d value is 1, and the switch port 1 is turned on. At this time, the synchronous speed error e v1 =V2-V1 enters the speed compensator 1 for calculation, and outputs the calculated current compensation command to the current loop controller input of the single-axis speed tracking control loop where motor 1 is located; while port 2 is disconnected, the current loop compensation value of motor 2 is 0. When motor 1 has strong tracking performance and motor 2 has weak tracking performance, the d value is 2, and switch port 2 is turned on. At this time, the synchronous speed error e v2 =V1-V2 enters the speed compensator 2 for calculation, and the calculated current compensation instruction is output to the current loop controller input end of the single-axis speed tracking control loop where motor 2 is located, and port 1 is disconnected, so the current loop compensation value of motor 1 is 0.

[0078] Step 3: Design of single-axis tracking-dual-axis synchronization composite motion controller: First, establish the dynamic model of the dual-drive motion system; secondly, design a single-axis tracking motion controller, and use the speed error signal as input to perform speed closed-loop sliding mode control; thirdly, design a dual-axis synchronization motion controller, and use the current error signal as input to perform current closed-loop PID control, thereby completing single-axis tracking-dual-axis synchronization composite motion control.

[0079] Step 3.1: Modeling method of dual-drive motion system: First, establish the dynamic equation of the dual-drive motion system motor, such as Figure 4 As shown: The formula is:

[0080] F m =F a +F f +F d (3)

[0081] Among them, F m is the driving force, F a is the inertial force, F f is the viscous friction force, F d are other disturbance forces, which are ignored in the modeling stage.

[0082] The driving force model is established based on the voltage balance equation and magnetic flux model of the permanent magnet synchronous motor:

[0083]

[0084] Where C is the motor driving force constant, P n is the number of motor pole pairs, ψ f is the effective magnetic flux generated by the permanent magnet, σ is the pole pitch, and i is the driving current.

[0085] According to formulas (3) and (4), the dynamic model of the dual-drive motion system is established:

[0086]

[0087] Where B is the viscous friction coefficient, k is the motor number, m is the load mass, m k is the primary mass of the motor, s(t) is the position signal of the linear motor as a function of time, and i(t) is the current signal of the linear motor as a function of time.

[0088] Step 3.2: Single-axis tracking motion controller design: Use the sliding mode control method as the speed closed-loop controller in the single-axis tracking motion controller. The difference between the target speed signal and the actual speed signal is converted into a corresponding current control instruction through the sliding mode control method, and the current control instruction is output to the input end of the current closed-loop controller to realize single-axis speed tracking control.

[0089] Step 3.3: Design of dual-axis synchronous motion controller: Use PID control method as the current closed-loop control method of the dual-axis synchronous motion controller. The input of the current controller combines the current control instruction of the single-axis tracking motion controller and the current compensation information of the synchronous error compensator. The current error signal is calculated based on the actual current signal fed back by the inverter drive. The voltage control instruction corresponding to the current error signal is calculated through the PID control method to realize dual-drive synchronous motion control between the two motors.

[0090] The sliding mode control method described in steps 2 and 3 includes the following steps:

[0091] Step 4.1: Design the sliding surface: Design the sliding surface based on the motor dynamics model. First, set the state variables x1 and x2:

[0092]

[0093] Among them, v ref is the target speed signal, and v is the actual speed signal.

[0094] Combining formula (6) with formula (5), the system state space equation is established:

[0095]

[0096] Wherein, the control input is u = i(t)′, and the mass of the load and the motor primary is M = m + m0;

[0097] Design sliding surface function based on system state space equation

[0098] s=cx1+x2 (8)

[0099] Among them, the design parameter c>0.

[0100] By differentiating formula (8), we can obtain the sliding surface derivative function:

[0101]

[0102] Step 4.2: Design the exponential approach rate: Based on the sliding surface function and the system state space equation, design the exponential approach rate used in the sliding mode control method:

[0103]

[0104] Among them, parameters ε>0, q>0;

[0105] Step 4.3: Sliding mode controller design: First, substitute the exponential approach rate formula (10) into the sliding surface derivative function formula (9) to establish a preliminary sliding mode controller:

[0106]

[0107] Substituting the control input u=i(t)′ into formula (11), we get the sliding mode controller equation:

[0108]

[0109] Among them, i is the current control variable.

[0110] The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principles of the present invention. These improvements should also be regarded as the scope of protection of the present invention.

Claims

1. A synchronous control method for a dual-drive motion system based on adaptive compensation of synchronization error, characterized in that The following steps are involved: Step 1: Adaptive synchronous control system design: First, design a parallel synchronous control architecture, using it to organize two single-axis speed tracking control loops and a synchronization error compensation control loop. Next, design a single-axis speed tracking control loop using a cascade closed-loop controller that combines speed closed-loop control with current closed-loop control. Finally, design a synchronization error compensation control loop, including a synchronization error calculation module, a tracking performance comparison switch, and a synchronization error compensator. Step 2: Design of a real-time synchronization error selective compensation strategy: First, design a tracking performance comparison switch to distinguish the two motors according to strong tracking performance and weak tracking performance at each sampling cycle; Next, a synchronous error calculation module is designed to obtain the synchronous speed error by calculating the difference between the actual speed signals of the two motors. Finally, a synchronous error compensator is designed to convert the synchronous speed error into a current compensation signal for the current closed-loop controller for motors with poor tracking performance. Step 3: Design of a single-axis tracking and dual-axis synchronous composite motion controller: First, establish the dynamic model of the dual-drive motion system. Next, design a single-axis tracking motion controller, using the velocity error signal as input for closed-loop velocity control. Finally, design a dual-axis synchronous motion controller, using the current error signal as input for closed-loop current control, thus completing the single-axis tracking and dual-axis synchronous composite motion control. The method for designing a real-time synchronization error selective compensation strategy comprises the following steps: Step 2.1: Tracking performance comparison switch design: Design a tracking performance comparison switch for evaluating the tracking performance of two motors. The switch uses the absolute position error and mean square position error between the actual position signal of each motor and the target position signal as the judgment basis. As shown in formula (1), the two motors are distinguished as strong tracking performance and weak tracking performance at each sampling cycle: first, the absolute position errors of the two motors are judged, and the motor with the larger absolute position error is regarded as weak tracking performance; if the absolute position errors of the two motors are equal, the mean square position error is judged, and the motor with the larger mean square position error is regarded as weak tracking performance; if the absolute position errors and mean square position errors of the two motors are equal, one motor is randomly selected as weak tracking performance; and the switch control signal of the tracking performance comparison switch is determined with the motor with weak tracking performance as the compensation object; Among them, S ref is the target position signal, S i is the actual position signal of motor number i, e s is the absolute position error, MSE is the mean square position error, τ is the current time, and t is the running time; Step 2.2: Synchronous error calculation module design: The synchronous error calculation module obtains the synchronous speed error E by calculating the difference between the actual speed signals of the two motors. v , the error is equal to the actual speed V of the motor for strong tracking performance 强 Subtract the actual speed V of the motor with weak tracking performance 弱 : E v =V 强 -V 弱 (2) Step 2.3: Synchronous error compensator design: The synchronous error compensator is divided into speed compensator 1 and speed compensator 2 according to the motor number i. The synchronous speed error is input into the speed compensator of the corresponding compensation object through the tracking performance comparison switch, and then the speed compensation is processed by the sliding mode control method to generate the current compensation signal of the current closed-loop controller in the corresponding compensation object.

2. The synchronous control method of a dual-drive motion system based on adaptive compensation of synchronization error according to claim 1, characterized in that: The adaptive synchronous control system design method comprises the following steps: Step 1.1: Design a parallel synchronous control architecture: Use a parallel synchronous control architecture to organize two single-axis speed tracking control loops. These two control loops receive the same target speed signal input but operate independently. The outputs of the two single-axis speed tracking control loops are connected to the input of the synchronous error compensation control loop. The actual speed and actual position signals output by the two motors are processed by the synchronous error compensation control loop and then input into the single-axis speed tracking control loop as current compensation commands. Step 1.2: Design a single-axis speed tracking control loop: The single-axis speed tracking control loop uses a cascade closed-loop controller that combines speed closed-loop control with current closed-loop control. The control loop also includes a vector controller (FOC), an inverter drive, and a linear motor. The target speed signal is input into the cascade closed-loop controller. The voltage signal processed by the controller is converted into a pulse signal by the vector controller, which controls the inverter drive to drive the linear motor. The actual current signal generated by the linear motor movement is fed back to the input of the current closed-loop controller, and the actual speed signal generated by the linear motor movement is fed back to the input of the speed closed-loop controller. Step 1.3: Design of synchronous error compensation control loop: The synchronous error compensation control loop consists of a synchronous error calculation module, a tracking performance comparison switch and a synchronous error compensator; the actual speed signals generated by the movement of the two motors are processed into synchronous speed errors by the synchronous error calculation module, and the actual position signals generated by the movement of the two motors are processed by the tracking performance comparison switch TPCS to obtain a switch control signal, which controls the selective compensation switch of the synchronous speed error and outputs the synchronous speed error to the synchronous error compensator of the corresponding compensation object. After speed compensation processing, it is input into the current closed-loop controller input end of the single-axis speed tracking control loop of the corresponding compensation object in the form of a current compensation instruction.

3. The synchronous control method of a dual-drive motion system based on adaptive compensation of synchronization error according to claim 1, characterized in that: The single-axis tracking-dual-axis synchronous composite motion controller design includes the following steps: Step 3.1: Modeling method of dual-drive motion system: First, establish the dynamic equation of the dual-drive motion system motor: as shown below: F m =F a +F f +F d (3) Among them, F m is the driving force, F a is the inertial force, F f is the viscous friction force, F d are other disturbance forces, which are ignored in the modeling stage; The driving force model is established based on the voltage balance equation and magnetic flux model of the permanent magnet synchronous motor: Where C is the motor driving force constant, P n is the number of motor pole pairs, ψ f is the effective flux generated by the permanent magnet, σ is the pole pitch, and i is the driving current; According to formulas (3) and (4), the dynamic model of the dual-drive motion system is established: Where B is the viscous friction coefficient, k is the motor number, m is the load mass, m k is the primary mass of the motor, s(t) is the function of the linear motor position signal with respect to time, and i(t) is the function of the linear motor current signal with respect to time; Step 3.2: Design a single-axis tracking motion controller: The single-axis tracking motion controller is a speed closed-loop controller using a sliding mode control method. The controller input signal is the motor speed error signal, that is, the difference between the target speed signal and the actual speed signal. The controller calculates the current control command corresponding to the speed error signal using the sliding mode control method to achieve single-axis tracking motion control, and outputs the current control command to the input of the current closed-loop controller. Step 3.3: Design of dual-axis synchronous motion controller: The dual-axis synchronous motion controller is a current closed-loop controller using the PID control method. It integrates the current control instruction of the single-axis tracking motion controller and the current compensation information of the synchronous error compensator as the control target of the current loop. The current error signal is calculated based on the actual current signal fed back by the inverter drive. The voltage control instruction corresponding to the current error signal is calculated through the PID control method to realize dual-axis synchronous motion control.

4. The synchronous control method of a dual-drive motion system based on adaptive compensation of synchronization error according to claim 3, characterized in that: The sliding mode control method comprises the following steps: Step 4.1: Sliding surface design: Design the sliding surface based on the motor dynamics model. First, set the state variables x1 and x2: Among them, v ref is the target speed signal, v is the actual speed signal, is the state quantity x1 after derivation; Combining formula (6) with formula (5), the system state space equation is established: Wherein, the control input is u = i(t)′, the mass of the load and the motor primary is M = m + m0, B is the viscous friction coefficient, and C is the motor driving force constant; Design the sliding surface function based on the system state space equation: s=cx1+x2 (8) Among them, the design parameter c>0; By differentiating formula (8), we can obtain the sliding surface derivative function: Step 4.2: Exponential approach rate design: Based on the sliding surface function and the system state space equation, design the exponential approach rate used in the sliding mode control method: Among them, the design parameters ε>0, q>0; sgn() is the sign function; Step 4.3: Sliding mode controller design: First, substitute the exponential approach rate formula (10) into the sliding surface derivative function formula (9) to establish a preliminary sliding mode controller: in It is the motor driving force constant C divided by the mass of the load and the motor primary and M; Then, the control input u = i(t)′ is substituted into formula (11) to obtain the final sliding mode controller: Among them, i is the current control variable.

Images