Multi-motor synchronous control system and method for TBM main drive system simulation test bench

Abstract

The present invention relates to a multi-motor synchronous control system for a TBM main drive system simulation test bench, comprising multiple motors installed on the TBM main drive system simulation test bench, each motor being provided with a pinion, each pinion being respectively meshed with the outer gear ring of the upper main slewing bearing, each motor being connected to a rotary transformer for receiving pulse signals from each motor; two motors forming a group, each group of motors being connected to a servo variable frequency drive, each servo variable frequency drive being interconnected with a synchronous motion control unit via an EtherCAT network, the synchronous motion control unit being provided with a virtual axis, the synchronous motion control unit being connected to a PLC control unit, the PLC control unit being a master station and the synchronous motion control unit being a slave station, and the PLC control unit being connected to a touch screen. The present invention also provides a multi-motor synchronous control method for the TBM main drive system simulation test bench. The present invention reduces synchronization errors and system chattering in multi-motor control, thereby improving the response speed and control accuracy of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of motor synchronous control, and in particular to a multi-motor synchronous control system and method for a TBM main drive system simulation test bench. Background Art

[0002] During the excavation process of a full-face tunnel boring machine (TBM), the drive motor in the main drive system may experience severe torque fluctuations due to the complex and changing geological environment and multi-field coupling. This can easily lead to torque imbalance in the drive motor and even cause abnormal damage to key components such as the drive shaft. Therefore, achieving synchronous control of multiple motors in the main drive system is one of the key technologies to ensure the safe and reliable operation of the TBM. Given the harsh working environment, confined working space, and complex structural space of the TBM main drive system, it is relatively difficult to obtain the vibration, temperature and other parameters of the main drive system under actual operating conditions. Typically, these parameters are measured on a test bench. The TBM main drive system simulation test bench can simulate the TBM main drive system and provide experimental parameters for simulated operation.

[0003] Considering the TBM cutterhead (such as Figure 1 The transmission characteristics of the upper main slewing bearing (shown in the figure) dictate a rigid connection between each motor and gear, resulting in forced synchronization between the motors. However, this speed synchronization is passive. Due to the meshing action of the gears, even though the motors have the same set speed, their output torques may vary. This can cause individual motors to rotate too fast, dramatically increasing their load, increasing motor heat, and in severe cases, even burning out.

[0004] Currently, the main synchronization control methods used in TBM main drive control systems include parallel control and master-slave control. While these methods are simple and easy to implement, the inherent coupling characteristics of the system mean that the synchronization of the entire system depends on the accuracy of the individual motor control technology and the stability of the load. When multiple motors are unevenly loaded, the system is prone to fluctuations or failure to reach a balanced state, thus affecting the normal operation of the TBM. To improve the synchronization performance of the drive system, a control structure with virtual axis deviation coupling is adopted. However, due to the error between the input given by the virtual axis and the output of the drive motor, as well as the corresponding coupling relationship between the various mechanical components of the test bench, the synchronization of the drive system is reduced. Therefore, there is an urgent need to develop a multi-motor synchronization control system and method based on a TBM main drive system simulation test bench. Summary of the Invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a multi-motor synchronous control system and method for a TBM main drive system simulation test bench.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a multi-motor synchronous control system of a TBM main drive system simulation test bench, comprising multiple motors installed on the TBM main drive system simulation test bench, each motor is provided with a pinion, each pinion is respectively engaged with the outer gear ring of the upper main slewing bearing, each motor is connected to a rotary transformer for receiving the pulse signal of each motor; every two motors form a group, each group of motors is connected to a servo frequency converter, each servo frequency converter is interconnected with a synchronous motion control unit through an EtherCAT network, a virtual axis is provided in the synchronous motion control unit, the synchronous motion control unit is connected to a PLC control unit, the PLC control unit is a master station, the synchronous motion control unit is a slave station, and the PLC control unit is connected to a touch screen.

[0007] Furthermore, the PLC control unit is also connected to a pressure sensor, a drive-end torque sensor, and a load-end torque sensor of the TBM main drive system simulation test bench. At the same time, the PLC control unit is communicatively connected to a computer.

[0008] Furthermore, the motor is an AC permanent magnet synchronous motor with a rated power of 3.7 kW, a rotation speed of 2000 r / min, and a maximum torque of 25 N·m.

[0009] Furthermore, the number of the motors is six.

[0010] The present invention also provides a multi-motor synchronous control method for a TBM main drive system simulation test bench, which is implemented using the multi-motor synchronous control system of the TBM main drive system simulation test bench, and includes the following steps:

[0011] S1, establish the electromechanical coupling mechanism model of the main drive system;

[0012] S2, setting a control structure combining deviation coupling and virtual axis in the PLC control unit to control the output speed and torque value of each motor and feed it back to the input end of the virtual axis in the synchronous motion control unit;

[0013] S3, establish the mathematical model of the dq-axis motor, construct a super-local sliding mode controller, design an improved non-singular fast terminal sliding mode surface, and introduce an adaptive power function into the exponential reaching law of the non-singular fast terminal sliding mode;

[0014] S4, establish a super-helical sliding mode disturbance observer model and an extended super-local model of the motor speed loop, design an extended sliding mode disturbance observer, and discretize the extended sliding mode disturbance observer. The super-helical sliding mode disturbance observer is used to observe the part of the super-local sliding mode controller containing external disturbances and parameter perturbations in real time, and the observation value is fed back to the super-local sliding mode controller to achieve synchronous control of each motor.

[0015] Furthermore, the electromechanical coupling mechanism model of the main drive system described in step S1 is:

[0016]

[0017] Where, i = 1, 2…6; k ld Indicates the torsional connection stiffness of the upper main slewing bearing; k mpo represents the torsional stiffness of the pinion and motor shaft; k pmi represents the time-varying meshing stiffness of the i-th pinion and the outer ring gear under different overturning degrees;

[0018] r bm Expressed as the base circle radius of the pinion; r bd is the base circle radius of the outer gear ring;

[0019] C ld Indicates the torsional damping of the upper main slewing bearing; C mpo Represents the torsional damping between the pinion and the shaft; C pmi represents the meshing damping between the i-th pinion and the outer ring gear at different overturning degrees; C psi represents the torsional damping of the motor;

[0020] I l Indicates the moment of inertia of the upper main slewing bearing; I d Indicates the moment of inertia of the outer ring gear; I mi represents the moment of inertia of the i-th pinion; J i represents the moment of inertia of the i-th motor;

[0021] θ l Represents the torque displacement of the upper main slewing bearing; θ d Represents the torque displacement of the outer ring gear; θ mi represents the torque displacement of the i-th pinion; θ si represents the torque displacement of the i-th motor;

[0022] T si represents the output torque of the i-th motor; T l Indicates the equivalent total torque borne by the upper main slewing bearing; T ei represents the electromagnetic torque of the i-th motor; D pmi represents the meshing damping force between the i-th pinion and the outer ring gear; F pmi represents the dynamic meshing force between the i-th pinion and the outer ring gear.

[0023] Furthermore, the step S3 specifically includes the following steps:

[0024] S301, establish the mathematical model of the motor on the dq axis:

[0025]

[0026] Where: u d represents the d-axis voltage, u q represents the q-axis voltage; L d Indicates the d-axis inductance, L q represents the q-axis inductance; i d represents the d-axis current, i q represents the q-axis current; R s represents the stator resistance, ψ represents the permanent magnet flux, ω e represents the rotor electrical angular velocity; f d and f q denote the disturbances caused by model parameter changes and external load changes, respectively;

[0027] f d and f q is defined as:

[0028]

[0029] Where, ΔR s , ΔL q , ΔL d and Δψ represent the R when the model parameters change and the external load changes, respectively. s , L q , L d and the changing values ​​of ψ;

[0030] In step S302, in order to estimate the unknown parameters of the motor, the following hyperlocal model is used:

[0031]

[0032] Among them, y and u represent the system output and control input respectively, x represents the state variable of the system, and y (v) is the v-th derivative of y and v ≥ 1, g(x) is a nonlinear Lipschitz bounded function that depends only on x, and K is a nonzero undetermined physical constant gain such that Ku has the same order as x;

[0033] S303, constructing a super-local sliding mode controller for the motor, specifically:

[0034]

[0035] Among them, α ω represents the q-axis current gain to be designed, β ω Indicates the speed gain to be designed, F ω Represents the set of parameter perturbations, load fluctuations and other unknown parameters in the system;

[0036] S304, design an improved non-singular fast terminal sliding surface, specifically:

[0037] 1) Define the speed error e as: e = ω r -ω e ;

[0038] Among them, ω r Indicates the motor target speed, ω e represents the rotor electrical angular velocity;

[0039] 2) Define the speed error e as the system state variable:

[0040]

[0041] Among them, x1 represents the system state error;

[0042] 3) Define the improved non-singular fast terminal sliding surface s as:

[0043]

[0044] Where p, q, λ2 and λ1 are constants, and p>0, q>0, 0<λ2<2, λ2<λ1, sgn() is a sign function;

[0045] 4) Introducing an adaptive power function into the exponential reaching law of the non-singular fast terminal sliding mode:

[0046]

[0047] Among them, k1, k2 and α are positive constants to be designed;

[0048] When the system state is about to reach the sliding surface, that is, |s| < 1, the speed reaches the term k1(|x1||s|) 1-αsgn(1-|s|) sgn(s) plays a dominant role, while the exponential reaches the term k2|s| 1+α sgn(s) will quickly approach 0. Obviously, k1(|x1||s|) 1+α with k2|s| 1+α are respectively less than k1|s| 1-α Compared with k2s, as |s| continues to decrease, the system chattering is effectively reduced while ensuring convergence.

[0049] Furthermore, step S4 specifically includes the following steps:

[0050] S401, establish a super-helical sliding mode disturbance observer model:

[0051]

[0052] Among them, s1 and u1 are state variables, β1 and β2 are sliding mode gain coefficients;

[0053] S402: Based on the motor hyperlocal model and according to the input and output of the motor speed loop control, an extended hyperlocal model of the motor speed loop is established:

[0054]

[0055] Where R(t) is F ω rate of change;

[0056] S403, design an extended sliding mode disturbance observer, specifically:

[0057]

[0058] in, is the real-time estimate of the motor speed by the observer; is the observer's real-time estimate of the total unknown part of the system; u smo is the sliding mode function to be designed; l is the sliding mode function u smo gain;

[0059] Define the observer errors e1 and e2 as:

[0060] when The error of super-helical sliding mode disturbance observer is realized to be 0, and the observer converges asymptotically;

[0061] satisfy Where ε is any positive constant;

[0062] Based on s1=e1, the super-helical sliding mode disturbance observer is discretized to obtain:

[0063]

[0064] Where T is the sampling period and k is a positive constant;

[0065] S404, using a super-helical sliding mode disturbance observer to observe in real time the part of the super-local sliding mode controller containing external disturbances and parameter perturbations, and feeding back the observed value e2 to the super-local sliding mode controller to achieve synchronous control of each motor.

[0066] Compared with the prior art, the present invention has the following beneficial effects:

[0067] 1. The present invention proposes a multi-motor synchronous control method, which divides the drive motors into regions, and divides every two motors into a group, which is connected to a servo variable frequency drive. After the present invention divides the multiple motors into regions, the system exhibits coupling characteristics, and adopts an improved control structure combining deviation coupling with a virtual main axis, which ensures the synchronization performance while being able to quickly generate synchronization compensation to make up for the adjustment delay. Compared with the multi-motor master-slave control strategy in the prior art, the transmission delay of the motor speed and torque signal is significantly reduced, thereby improving the dynamic response characteristics of the system. The present invention can simulate the eccentric load and overload phenomena that occur when the motor position and speed tracking of the TBM main drive system are affected by the nonlinearity of friction tooth gap during actual operation.

[0068] 2. The present invention is applicable to the synchronous control of more than two motors. Based on the original virtual axis control strategy, the present invention simplifies the system design and solves the problem of large interference in the virtual axis control method under high-power system applications, thereby improving the adaptability of the system, reducing the maintenance difficulty, and enhancing the system's response speed and control accuracy.

[0069] 3. This invention uses a speed disturbance observer and, based on the feedback compensation signal processed by the super-helical sliding mode observer, modifies the q-axis current reference and the actual speed reference of each motor. This improved sliding mode controller further enhances the motor's speed dynamics.

[0070] 4. This invention incorporates an adaptive power function into the terminal sliding mode exponential convergence law and designs a novel adaptive convergence law to adjust the system state variables. By constructing a super-helical sliding mode disturbance observer, this invention improves the system's ability to observe disturbances and its sensitivity to motor speed and feedback. In the presence of parameter disturbances and sudden load changes, the system can estimate the total unknown in real time and feed it back to the speed control link, effectively reducing system synchronization error. While ensuring convergence, this invention effectively reduces system chattering. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The illustrative examples of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0072] Figure 1 This is a structural diagram of the TBM main drive system simulation test bench in the present invention;

[0073] Figure 2 This is a structural diagram of the multi-motor synchronous control system of the TBM main drive system simulation test bench in the present invention;

[0074] Figure 3This is a diagram of the torque coupling structure between the pinion of the motor and the outer gear ring of the upper main slewing support in the present invention;

[0075] Figure 4 This is a block diagram of the electronic control principle of the multi-motor synchronous control system of the TBM main drive system simulation test bench in the present invention;

[0076] Figure 5 This is a flow chart of the super-helical sliding mode disturbance observer in the present invention for real-time estimation of unknown parts of the system and feedback compensation;

[0077] Figure 6 This is a graph showing the torque output of six motors under sudden load observation according to the present invention;

[0078] In the figure: 1. Motor; 2. Pinion; 3. Upper main slewing bearing; 4. Outer ring gear; 5. Servo frequency converter; 6. Synchronous motion control unit; 7. PLC control unit; 8. Touch screen; 9. Pressure sensor; 10. Drive-end torque sensor; 11. Load-end torque sensor; 12. Computer. DETAILED DESCRIPTION

[0079] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0080] Reference Figure 1 The TBM main drive system simulation test bench in this invention is a TBM main drive system multi-source signal online monitoring simulation test bench disclosed in patent publication number CN116577096A. The multi-motor synchronous control system and method of this invention are both implemented based on the TBM main drive system simulation test bench.

[0081] Example 1

[0082] Reference Figure 1 and Figure 2The multi-motor 1 synchronous control system of the TBM main drive system simulation test bench includes multiple motors 1 installed on the TBM main drive system simulation test bench, each motor 1 is provided with a pinion 2, each pinion 2 is respectively engaged with the outer gear ring 4 of the upper main slewing bearing 3, and each motor 1 is connected to a rotary transformer (not shown in the figure) for receiving the pulse signal of each motor 1; every two motors 1 form a group, and each group of motors 1 is connected to a servo frequency converter 5, and each servo frequency converter 5 is interconnected with a synchronous motion control unit 6 through an EtherCAT network. A virtual axis is provided in the synchronous motion control unit 6, and the virtual axis feeds back the current loop, position loop, and torque loop data of the motor 1 at the output end of the servo frequency converter to the input end for adjustment. The synchronous motion control unit 6 is connected to a PLC control unit 7, the PLC control unit 7 is a master station, and the synchronous motion control unit 6 is a slave station. The PLC control unit 7 is connected to a touch screen 8.

[0083] The touch screen 8 is provided with a human-machine interactive interface for setting the parameters of each motor 1 and the start, stop and speed regulation instructions issued by the user;

[0084] Each rotary transformer transmits the received pulse signal of each motor 1 to the servo frequency converter 5. Each servo frequency converter 5 identifies the signal transmitted by the rotary transformer and transmits it to the synchronous motion control unit 6 through the EtherCAT network. The PLC control unit 7 receives the start, stop and speed regulation instructions issued by the user and sends them to the synchronous motion control unit 6. The synchronous motion control unit 6 controls the rotation of the virtual axis and sends speed regulation signals and start and stop control signals to the servo frequency converter 5. Multiple motors 1 are interlocked with the virtual axis and the torque output of the six motors 1 is automatically adjusted according to the set parameters of the current loop, position loop and torque loop of the virtual axis.

[0085] The PLC control unit 7 is also connected to a pressure sensor 9 , a drive-end torque sensor 10 , and a load-end torque sensor 11 of the TBM main drive system simulation test bench. At the same time, the PLC control unit 7 is in communication with a computer 12 .

[0086] There are three pressure sensors 9, six drive-end torque sensors 10, and one load-end torque sensor 11. The drive-end torque sensor 10 collects the output torque data of each motor 1 in real time, and the load-end torque sensor 11 collects the input torque data of the load device in real time. The pressure sensor 9 collects the pressure data of the loading hydraulic cylinder and transmits it to the PLC control unit 7, and observes the equipment operation status in real time through the touch screen 8.

[0087] The motor 1 is an AC permanent magnet synchronous motor 1 with a rated power of 3.7 kW, a rotation speed of 2000 r / min, and a maximum torque of 25 N·m.

[0088] The number of the motors 1 is six.

[0089] The multi-motor 1 synchronous control system of the TBM main drive system simulation test bench of the present invention achieves stable closed-loop speed control, synchronously collects data required for experiments, and enables rapid, stable, and accurate numerical storage and recording. In this embodiment, the PLC control unit 7 is a programmable controller system with a Lanpufeng 2000 as the master and a synchronous motion control unit 6 as the slave. The programmable controller 10 uses DC24V for data acquisition and control. The PLC control unit 7 uses CODESYS programming, which is highly versatile and portable, facilitating later program modifications. The touch screen 8 digitally displays a human-machine interface for setting the interlocking enable for each motor 1. Based on user-issued start / stop and speed control commands, the PLC control unit 7 acts as the master to send speed control signals and start / stop control signals to each servo variable frequency drive 5. The touch screen 8 allows experimenters to monitor program execution and perform hardware diagnostics. The touch screen 8 communicates with the PLC control unit 7 to collect, process, store, and display networked data, creating a customized control interface that facilitates operator operation. The electrical control system of the TBM main drive system multifunctional test bench is field-level automated, utilizing fieldbus control technology based on the MODBUS protocol. Furthermore, the PLC control unit 7 communicates with the computer 12 via the industrial Ethernet protocol, and its automation level can be raised to the monitoring level and the management level, thereby realizing remote testing and monitoring of the shield machine.

[0090] The technical data involved in the multi-motor 1 synchronous control system of the present invention are shown in Table 1:

[0091] Table 1 Technical parameters of multi-motor synchronous control system

[0092]

[0093] Example 2

[0094] The multi-motor synchronous control method of the TBM main drive system simulation test bench is implemented using the multi-motor synchronous control system of the TBM main drive system simulation test bench described in the first embodiment, and includes the following steps:

[0095] Reference Figure 1-Figure 3 , S1, establish the electromechanical coupling mechanism model of the main drive system:

[0096]

[0097] Where, i = 1, 2…6; k ld k represents the torsional connection stiffness of the upper main slewing bearing 3; mpo represents the torsional stiffness of pinion 2 and the motor shaft; k pmi represents the time-varying meshing stiffness of the i-th pinion 2 and the outer ring gear 4 at different overturning degrees;

[0098] r bm Expressed as the base circle radius of pinion 2; r bd is the base circle radius of the outer gear ring 4;

[0099] C ld Represents the torsional damping of the upper main slewing bearing 3; C mpo Represents the torsional damping between pinion 2 and the shaft; C pmi represents the meshing damping between the i-th pinion 2 and the outer ring gear 4 at different overturning degrees; C psi represents the torsional damping of motor 1;

[0100] I l I represents the moment of inertia of the upper main slewing bearing 3; d Represents the moment of inertia of the outer ring gear 4; I mi represents the moment of inertia of the i-th pinion 2; J i represents the moment of inertia of the i-th motor 1;

[0101] θ l Represents the torque displacement of the upper main slewing bearing 3; θ d Represents the torque angular displacement of the outer gear ring 4; θ mi represents the torque angular displacement of the i-th pinion 2; θ si represents the torque angular displacement of the i-th motor 1;

[0102] T si represents the output torque of the i-th motor 1; T l Indicates the equivalent total torque borne by the upper main slewing bearing 3; T ei represents the electromagnetic torque of the i-th motor 1; D pmi represents the meshing damping force between the i-th pinion 2 and the outer ring gear 4; F pmi represents the dynamic meshing force between the i-th pinion 2 and the outer ring gear 4;

[0103] Reference Figure 4 S2, a control structure combining deviation coupling and virtual axis is set in the PLC control unit to control the output speed and torque value of each motor 1, which is fed back to the input end of the virtual axis in the synchronous motion control unit, and the output of the synchronous motion control unit is transmitted to the servo variable frequency drive 5 to realize the compensation correction of the speed reference value. Specifically, the following steps are included:

[0104] Reference Figure 4The control structure shown combines deviation coupling with the virtual axis. The virtual axis speed loop PI controller outputs set values ​​to the six motors 1 and receives feedback on the speed error. The speed error is weighted and coupled with the extreme value and mean value as the synchronization error. The synchronization error is multiplied by different weights and then added to obtain the synchronization compensation. The synchronization compensation is output to the forward channel of the current loop of each motor 1 to achieve error compensation, ensuring that the control parameters of the six drive motors 1 are basically consistent with those of the virtual axis.

[0105] S3, establishes a mathematical model of the dq-axis motor 1, constructs a super-local sliding mode controller, designs an improved non-singular fast terminal sliding mode surface, and introduces an adaptive power function into the exponential reaching law of the non-singular fast terminal sliding mode. Specifically, the following steps are included:

[0106] S301, establish a mathematical model of the motor 1 on the dq axis:

[0107]

[0108] Where: u d represents the d-axis voltage, u q represents the q-axis voltage; L d Indicates the d-axis inductance, L q represents the q-axis inductance; i d represents the d-axis current, i q represents the q-axis current; R s represents the stator resistance, ψ represents the permanent magnet flux, ω e represents the rotor electrical angular velocity; f d and f q denote the disturbances caused by model parameter changes and external load changes, respectively;

[0109] Among them, f d and f q is defined as:

[0110]

[0111] Where, ΔR s , ΔL q , ΔL d and Δψ represent the R when the model parameters change and the external load changes, respectively. s , L q , L d and the changing values ​​of ψ;

[0112] In step S302, in order to estimate the unknown parameters of the motor 1, the following hyperlocal model is used:

[0113]

[0114] Among them, y and u represent the system output and control input respectively, x represents the state variable of the system, and y (v) is the v-th derivative of y and v ≥ 1, g(x) is a nonlinear Lipschitz bounded function that depends only on x, and K is a nonzero undetermined physical constant gain such that Ku has the same order as x;

[0115] S303, constructing a super-local sliding mode controller for the motor, specifically:

[0116]

[0117] Among them, α ω represents the q-axis current gain to be designed, β ω Indicates the speed gain to be designed, F ω Represents the set of parameter perturbations, load fluctuations and other unknown parameters in the system;

[0118] S304, design an improved non-singular fast terminal sliding surface, specifically:

[0119] 1) Define the speed error e as: e = ω r -ω e ;

[0120] Among them, ω r Indicates the target speed of motor 1 (the speed value set by the virtual axis), ω e represents the rotor electrical angular velocity;

[0121] 2) Define the speed error e as the system state variable:

[0122]

[0123] Among them, x1 represents the system state error;

[0124] 3) Define the improved non-singular fast terminal sliding surface s as:

[0125]

[0126] Where p, q, λ2 and λ1 are constants, and p>0, q>0, 0<λ2<2, λ2<λ1, sgn() is a sign function;

[0127] 4) Introducing an adaptive power function into the exponential reaching law of the non-singular fast terminal sliding mode:

[0128]

[0129] Among them, k1, k2 and α are positive constants to be designed;

[0130] When the system state is about to reach the sliding surface, that is, |s| < 1, the speed reaches the term k1(|x1||s|) 1-αsgn(1-|s|) sgn(s) plays a dominant role, while the exponential reaches the term k2|s| 1+α sgn(s) will quickly approach 0. Obviously, k1(|x1||s|) 1+α with k2|s| 1+α are respectively less than k1|s| 1-α With k2s, as |s| continues to decrease, the system chattering is effectively reduced while ensuring convergence;

[0131] S4, establish the super-helical sliding mode disturbance observer model and the extended super-local model of the motor speed loop, design the extended sliding mode disturbance observer, and discretize the extended sliding mode disturbance observer. The super-helical sliding mode disturbance observer is used to observe the part of the super-local sliding mode controller containing external disturbances and parameter perturbations in real time, and the observation value e2 is fed back to the super-local sliding mode controller to achieve synchronous control of each motor 1 (refer to Figure 5 ), specifically including the following steps:

[0132] S401, establish a super-helical sliding mode disturbance observer model:

[0133]

[0134] Among them, s1 and u1 are state variables, β1 and β2 are sliding mode gain coefficients;

[0135] S402: Based on the motor hyperlocal model and according to the input and output of the speed loop control of motor 1, an extended hyperlocal model of the motor speed loop is established:

[0136]

[0137] Where R(t) is F ω rate of change;

[0138] S403, design an extended sliding mode disturbance observer, specifically:

[0139]

[0140] in, is the real-time estimate of the speed of motor 1 by the observer; is the observer's real-time estimate of the total unknown part of the system; u smo is the sliding mode function to be designed; l is the sliding mode function u smo gain;

[0141] Define the observer errors e1 and e2 as:

[0142] when The error of super-helical sliding mode disturbance observer is realized to be 0, and the observer converges asymptotically;

[0143] satisfy Where ε is any positive constant;

[0144] Based on s1=e1, the extended sliding mode disturbance observer equation is discretized to obtain:

[0145]

[0146] Where T is the sampling period and k is a positive constant;

[0147] S404 , using a super-helical sliding mode disturbance observer to observe in real time the part of the super-local sliding mode controller containing external disturbances and parameter perturbations, and feeding back the observation value e2 to the super-local sliding mode controller to achieve synchronous control of each motor 1 .

[0148] When performing multi-motor synchronous control, the present invention first powers on the multifunctional test bench for the TBM main drive system. Touchscreen 8 on the console enables and interlocks the six motors 1 with one click, and the speed of the TBM main drive system test bench is set to 2 m / s. Communication with the PLC control unit 7 is established via a computer 12. Using CODESYS software, the Ethernet IP address is set to 192.168.5.100 to synchronize data with the PLC control unit 7. At this point, the PLC control unit 7 can issue commands to the test bench control system.

[0149] Use EASY software to synchronize data with the synchronous motion control unit 6 in the test bench. The IP address is set to the same as the address of the above-mentioned PLC control unit 7. After the synchronous motion control unit 6 receives the synchronization instruction issued by the PLC control unit 7, the synchronous motion control unit 6 sets the internal virtual axis parameters, which controls the rotation of the virtual axis. The six motors 1 are interlocked with the virtual axis, and the torque output of the six motors 1 is automatically adjusted according to the set parameters of the current loop, position loop, and torque loop of the virtual axis. Without any load, the six motors 1 meet basically consistent speed and torque, realizing multi-motor synchronous control.

[0150] Start the test bench hydraulic system, push the hydraulic push rod to increase pressure, and push it downward by 10N. At this time, the synchronous motion control unit 6 quickly responds and adjusts the current loop, position loop, and torque loop outputs of the six motors 1 to achieve synchronous control of the six motors 1.

[0151] According to the above steps, the speed and torque values ​​of each motor 1 can be obtained. The output of the synchronous motion control unit 6 and the speed setting jointly act on the speed setting of each group of servo frequency conversion drive 5 loops to realize speed, torque, and displacement multi-feedback control, thereby achieving speed synchronization control, torque balance, and displacement consistency of multiple loop motors 1.

[0152] The target speed of motor 1 is set to 2000 r / s, and the load mutation range of motor 1 is set to 3-20 N at 0.5 s. The model parameters are shown in Table 2.

[0153] Table 2 Motor 1 model parameters

[0154]

[0155] Apply the parameters in Table 4 to Figure 4 and Figure 5 In the control model designed by Figure 6 As shown, at t = 0.5s, the six motors 1 are suddenly loaded, and the load torque is T l =10N, by Figure 6 It can be seen that the super-helical sliding mode control has small speed fluctuations and a short synchronization response time when the load is disturbed. In addition, the torque curve under the improved super-local sliding mode controller and super-helical sliding mode disturbance observer has a fast response speed, small oscillation, short recovery time, and good motor synchronization effect.

[0156] It can be seen from this that under load, through experimental verification, the synchronous control method of the present invention can control the torque balance time of each motor 1 within 0.1s, with a fast response time and good synchronization effect, which can meet the working requirements of the TBM main drive system.

[0157] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements to the present invention are intended to fall within the scope of protection of the present invention.

Claims

1. A multi-motor synchronous control method for a TBM main drive system simulation test bench is implemented using a multi-motor synchronous control system of the TBM main drive system simulation test bench. The multi-motor synchronous control system of the TBM main drive system simulation test bench includes multiple motors installed on the TBM main drive system simulation test bench, each motor is provided with a pinion, each pinion is respectively engaged with the outer gear ring of the upper main slewing bearing, and each motor is connected to a rotary transformer for receiving pulse signals of each motor; every two motors form a group, and each group of motors is connected to a servo variable frequency drive, and each servo variable frequency drive is interconnected with a synchronous motion control unit via an EtherCAT network. The synchronous motion control unit is provided with a virtual axis, and the synchronous motion control unit is connected to a PLC control unit. The PLC control unit is a master station and the synchronous motion control unit is a slave station. The PLC control unit is connected to a touch screen; It is characterized by: The following steps are involved: S1, establish the electromechanical coupling mechanism model of the main drive system; S2, setting a control structure combining deviation coupling and virtual axis in the PLC control unit to control the output speed and torque value of each motor and feed it back to the input end of the virtual axis in the synchronous motion control unit; S3, establish the mathematical model of the dq-axis motor, construct a super-local sliding mode controller, design an improved non-singular fast terminal sliding mode surface, and introduce an adaptive power function into the exponential reaching law of the non-singular fast terminal sliding mode; S4, establish a super-helical sliding mode disturbance observer model and an extended super-local model of the motor speed loop, design an extended sliding mode disturbance observer, and discretize the extended sliding mode disturbance observer. The super-helical sliding mode disturbance observer is used to observe the part of the super-local sliding mode controller containing external disturbances and parameter perturbations in real time, and the observation value is fed back to the super-local sliding mode controller to achieve synchronous control of each motor.

2. The multi-motor synchronous control method for the TBM main drive system simulation test bench according to claim 1 is characterized in that: The electromechanical coupling mechanism model of the main drive system described in step S1 is: Where, i = 1, 2…6; k ld Indicates the torsional connection stiffness of the upper main slewing bearing; k mpo represents the torsional stiffness of the pinion and motor shaft; k pmi represents the time-varying meshing stiffness of the i-th pinion and the outer ring gear under different overturning degrees; r bm Expressed as the base circle radius of the pinion; r bd is the base circle radius of the outer gear ring; C ld Indicates the torsional damping of the upper main slewing bearing; C mpo Represents the torsional damping between the pinion and the shaft; C pmi represents the meshing damping between the i-th pinion and the outer ring gear at different overturning degrees; C psi represents the torsional damping of the motor; I l Indicates the moment of inertia of the upper main slewing bearing; I d Indicates the moment of inertia of the outer ring gear; I mi represents the moment of inertia of the i-th pinion; J i represents the moment of inertia of the i-th motor; θ l Represents the torque displacement of the upper main slewing bearing; θ d Represents the torque angular displacement of the outer ring gear; θ mi represents the torque angular displacement of the i-th pinion; θ si represents the torque angular displacement of the i-th motor; T si represents the output torque of the i-th motor; T l Indicates the equivalent total torque borne by the upper main slewing bearing; T ei represents the electromagnetic torque of the i-th motor; D pmi represents the meshing damping force between the i-th pinion and the outer ring gear; F pmi represents the dynamic meshing force between the i-th pinion and the outer ring gear.

3. The multi-motor synchronous control method for a TBM main drive system simulation test bench according to claim 1, characterized in that: The step S3 specifically includes the following steps: S301, establish the mathematical model of the motor on the dq axis: Where: u d represents the d-axis voltage, u q represents the q-axis voltage; L d Indicates the d-axis inductance, L q represents the q-axis inductance; i d represents the d-axis current, i q represents the q-axis current; R s represents the stator resistance, ψ represents the permanent magnet flux, ω e represents the rotor electrical angular velocity; f d and f q denote the disturbances caused by model parameter changes and external load changes, respectively; f d and f q is defined as: Where, ΔR s , ΔL q , ΔL d and Δψ represent the R when the model parameters change and the external load changes, respectively. s , L q , L d , and ψ; In step S302, in order to estimate the unknown parameters of the motor, the following hyperlocal model is used: Among them, y and u represent the system output and control input respectively, x represents the state variable of the system, and y (v) is the v-th derivative of y and v ≥ 1, g(x) is a nonlinear Lipschitz bounded function that depends only on x, and K is a nonzero undetermined physical constant gain such that Ku has the same order as x; S303, constructing a super-local sliding mode controller for the motor, specifically: Among them, α ω represents the q-axis current gain to be designed, β ω Indicates the speed gain to be designed, F ω Represents the set of parameter perturbations, load fluctuations and other unknown parameters in the system; S304, design an improved non-singular fast terminal sliding surface, specifically: 1) Define the speed error e as: e = ω r -ω e ; Among them, ω r Indicates the motor target speed, ω e represents the rotor electrical angular velocity; 2) Define the speed error e as the system state variable: Among them, x1 represents the system state error; 3) Define the improved non-singular fast terminal sliding surface s as: Where p, q, λ2 and λ1 are constants, and p>0, q>0, 0<λ2<2, λ2<λ1, sgn() is a sign function; 4) Introducing an adaptive power function into the exponential reaching law of the non-singular fast terminal sliding mode: Among them, k1, k2 and α are positive constants to be designed; When the system state is about to reach the sliding surface, that is, |s| < 1, the speed reaches the term k1(|x1||s|) 1-αsgn(1-| s |) sgn(s) plays a dominant role, while the exponential reaches the term k2|s| 1+α sgn(s) will quickly approach 0. Obviously, k1(|x1||s|) 1+α with k2|s| 1+α are respectively less than k1|s| 1-α Compared with k2s, as |s| continues to decrease, the system chattering is effectively reduced while ensuring convergence.

4. The multi-motor synchronous control method for a TBM main drive system simulation test bench according to claim 1, characterized in that: Step S4 specifically includes the following steps: S401, establish a super-helical sliding mode disturbance observer model: Among them, s1 and u1 are state variables, β1 and β2 are sliding mode gain coefficients; S402: Based on the motor hyperlocal model and according to the input and output of the motor speed loop control, an extended hyperlocal model of the motor speed loop is established: Where R(t) is F ω rate of change; S403, design an extended sliding mode disturbance observer, specifically: in, is the real-time estimate of the motor speed by the observer; is the observer's real-time estimate of the total unknown part of the system; u smo is the sliding mode function to be designed; l is the sliding mode function u smo gain; Define the observer errors e1 and e2 as: when The error of super-helical sliding mode disturbance observer is realized to be 0, and the observer converges asymptotically; satisfy Where ε is any positive constant; Based on s1=e1, the super-helical sliding mode disturbance observer is discretized to obtain: Where T is the sampling period and k is a positive constant; S404, using a super-helical sliding mode disturbance observer to observe in real time the part of the super-local sliding mode controller containing external disturbances and parameter perturbations, and feeding back the observed value e2 to the super-local sliding mode controller to achieve synchronous control of each motor.

5. The multi-motor synchronous control method for a TBM main drive system simulation test bench according to claim 1, characterized in that: The PLC control unit is also connected to a pressure sensor, a drive-end torque sensor, and a load-end torque sensor of the TBM main drive system simulation test bench. At the same time, the PLC control unit is connected to a computer for communication.

6. The multi-motor synchronous control method for a TBM main drive system simulation test bench according to claim 1, characterized in that: The motor is an AC permanent magnet synchronous motor with a rated power of 3.7 kW, a rotation speed of 2000 r / min, and a maximum torque of 25 N·m.

7. The multi-motor synchronous control method for a TBM main drive system simulation test bench according to claim 1, characterized in that: The number of the motors is six.

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