Dual-motor coupling hybrid cutting system of coal mining machine and control method of dual-motor coupling hybrid cutting system

Abstract

The invention provides a dual-motor coupling hybrid cutting system of a coal mining machine and a control method of the dual-motor coupling hybrid cutting system. The dual-motor coupling hybrid cutting system comprises an axial magnetic flux motor, an active differential mechanism, a left electric control clutch, a left cutting motor, a left torque synthesizer, a right electric control clutch, a right cutting motor, a right torque synthesizer, a left sensor group, a right sensor group and a controller, the method comprises the following steps: controlling the left cutting motor and the right cutting motor to start to work synchronously; first current data of a left cutting motor and second current data of a right cutting motor are obtained; whether overload occurs is judged according to the current data, and if yes, real-time current error and self-adaptive gain updating is carried out; through the engagement or disengagement action of the clutch, the dynamic assistance of the cutting motor is realized, and the distribution of the auxiliary torque is dynamically adjusted. The system and method are high in intelligent degree, dynamic management and smooth switching of auxiliary power can be achieved, and it can be ensured that the cutting system can effectively cope with various load change working conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent control, and in particular is a dual-motor coupled hybrid cutting system for a coal mining machine and a control method thereof. Background Art

[0002] As the core equipment in coal mining production, the performance and efficiency of coal mining machines are directly related to the output and safety of coal mining. The traditional coal mining machine cutting part mainly adopts the electric-hydraulic hybrid drive mode, that is, the electric motor drives the hydraulic pump to output high-pressure oil, and then the high-pressure oil drives the hydraulic motor to operate, and finally the output power drives the cutting drum to rotate. Although the use of hydraulics as an auxiliary power supply has certain flexibility and controllability, it also has many problems such as low energy transmission efficiency and complex system.

[0003] With the increase in the depth of coal mining and the complexity of coal seam conditions, the power and torque requirements of the cutting part of the coal mining machine are also increasing. The use of dual motors as the main power source can provide high power density and precise torque control to meet the operating requirements under complex working conditions. The dual motor drive has the advantages of fast response speed and high control accuracy. It can flexibly adjust the output under different load conditions to ensure the stable and efficient operation of the cutting part. In addition, through the coordinated work of the dual motors, the dynamic balance of the system load can be achieved, and the overall performance and efficiency of the coal mining machine can be improved. However, in the prior art, there is a lack of cutting systems and control methods that can efficiently integrate dual motor drives, which makes the cutting system driven by dual motors in the prior art unstable. At the same time, the work efficiency needs to be further improved. For this reason, it is urgent to provide a new coal mining machine electric-electric hybrid cutting system and its control method. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a coal mining machine dual-motor coupled hybrid cutting system and a control method thereof. The system has a reasonable structure, good stability, and a high degree of intelligence. It has a sensitive response speed, can realize dynamic management and smooth switching of auxiliary power, and can ensure that the cutting system can effectively cope with various load change conditions. The method combines the output of the reasonably distributed auxiliary torque with the torque of the cutting motor, which can ensure that the coal mining machine can still maintain an efficient and stable working state under complex working conditions.

[0005] In order to achieve the above-mentioned object, the present invention provides a coal mining machine dual-motor coupled hybrid cutting system, including an axial flux motor, an active differential, a left electronically controlled clutch, a left cutting motor, a left torque synthesizer, a right electronically controlled clutch, a right cutting motor, a right torque synthesizer, a left sensor group, a right sensor group and a controller;

[0006] The output shaft of the axial flux motor is connected to the input shaft of the active differential;

[0007] One input end of the left torque synthesizer is connected to the left output shaft of the active differential through the left electronically controlled clutch, and the other input end is connected to the output shaft of the left cutting motor;

[0008] The left electronically controlled clutch comprises a left hydraulic clutch, a left electromagnetic reversing valve, a left motor, a left working pressure valve, a left overflow valve and a left hydraulic pump; the left hydraulic clutch comprises a left clutch hydraulic cylinder 1 and a left clutch hydraulic cylinder 2; the left motor is coaxially connected to the left hydraulic pump; the oil suction port of the left hydraulic pump is connected to the hydraulic oil tank, and the oil discharge port output of the left hydraulic pump is divided into two paths, one of which is connected to the P port of the left electromagnetic reversing valve through a pipeline, and the other is connected to the oil inlet of the left working pressure valve; the oil outlet of the left working pressure valve is divided into two paths, one of which is respectively connected to the rod chamber of the left clutch hydraulic cylinder 1 and the rod chamber of the left clutch hydraulic cylinder 2, and the other is connected to the hydraulic oil tank through the left overflow valve; the T port of the left electromagnetic reversing valve is connected to the hydraulic oil tank through a pipeline, its A port is connected to the rodless chamber of the left clutch hydraulic cylinder 1 through a pipeline, and its B port is connected to the rodless chamber of the left clutch hydraulic cylinder 2 through a pipeline;

[0009] One input end of the right torque synthesizer is connected to the right output shaft of the active differential through the right electronically controlled clutch, and the other input end is connected to the output shaft of the right cutting motor;

[0010] The right electronically controlled clutch comprises a right hydraulic clutch, a right electromagnetic reversing valve, a right motor, a right working pressure valve, a right overflow valve and a right hydraulic pump; the right hydraulic clutch comprises a right clutch hydraulic cylinder 1 and a right clutch hydraulic cylinder 2; the right motor is coaxially connected to the right hydraulic pump; the oil suction port of the right hydraulic pump is connected to the hydraulic oil tank, and the oil discharge port output of the right hydraulic pump is divided into two paths, one of which is connected to the P port of the right electromagnetic reversing valve through a pipeline, and the other is connected to the oil inlet of the right working pressure valve; the oil outlet of the right working pressure valve is divided into two paths, one of which is respectively connected to the rod chamber of the right clutch hydraulic cylinder 1 and the rod chamber of the right clutch hydraulic cylinder 2, and the other is connected to the hydraulic oil tank through the right overflow valve; the T port of the right electromagnetic reversing valve is connected to the hydraulic oil tank through a pipeline, its A port is connected to the rodless chamber of the right clutch hydraulic cylinder 1 through a pipeline, and its B port is connected to the rodless chamber of the right clutch hydraulic cylinder 2 through a pipeline.

[0011] The left sensor group includes a left current sensor and a left speed sensor; the left current sensor is connected to the left cutting motor and is used to collect the current signal of the left cutting motor in real time; the left speed sensor is connected to the left cutting motor and is used to collect the speed signal of the left cutting motor in real time;

[0012] The right sensor group includes a right current sensor and a right speed sensor; the right current sensor is connected to the right cutting motor and is used to collect the current signal 2 of the right cutting motor in real time; the right speed sensor is connected to the right cutting motor and is used to collect the speed signal 2 of the right cutting motor in real time;

[0013] The controller is respectively connected with the left sensor group, the right sensor group, the active differential, the left cutting motor, the left electromagnetic reversing valve, the left motor, the right electromagnetic reversing valve, the right motor and the right cutting motor.

[0014] As a preference, the controller is a PLC controller.

[0015] As a preferred embodiment, the left solenoid reversing valve and the right solenoid reversing valve are both three-position four-way solenoid reversing valves. When they work in the left position, the oil circuit between their P port and A port is connected, and the oil circuit between their T port and B port is connected. When they work in the middle position, their P port is cut off, and their T port, A port and B port are connected to each other. When they work in the right position, the oil circuit between their P port and B port is connected, and the oil circuit between their T port and A port is connected.

[0016] In the present invention, the output shaft of the axial flux motor is connected to the input shaft of the active differential, and the left output shaft and the right output shaft of the active differential are respectively output to the left cutting system and the right cutting system, which can provide additional driving force for the left cutting system and the right cutting system. Since the axial flux motor has the advantages of compact structure, high power density, high efficiency, etc., it is suitable for providing stable driving force in a limited space. In this way, by adding an axial flux motor, a stable additional driving force can be provided for the cutting system, so as to effectively deal with the situation where the left cutting motor is overloaded and the right cutting motor is overloaded, which can ensure the stable and reliable cutting operation of the coal mining machine and can be conducive to improving the coal mining efficiency. The unilateral output shaft of the active differential is connected to an input end of the unilateral torque synthesizer through a unilateral electronically controlled clutch, and at the same time, the other input end of the unilateral torque synthesizer is connected to the output shaft of the unilateral cutting motor. In this way, the output of the unilateral cutting motor and the unilateral output of the active differential can be efficiently coupled by using the unilateral torque synthesizer, and then the total output after coupling can be used to efficiently drive the unilateral cutting drum to perform cutting operations. At the same time, the control of the engagement and disengagement of the unilateral electronically controlled clutch can be achieved by controlling the unilateral electromagnetic reversing valve, and then the connection or disengagement process of the additional driving force can be conveniently controlled according to the load requirements, and the dynamic management and smooth switching of the auxiliary power can be achieved, ensuring that the cutting system can effectively cope with various load change conditions. The unilateral hydraulic clutch is provided with clutch hydraulic cylinders one and two at the same time, and the clutch hydraulic cylinders one and two are respectively connected to the A port and the B port of the unidirectional electromagnetic reversing valve. When one clutch hydraulic cylinder fails, the other clutch hydraulic cylinder can still be used to ensure the normal operation of the clutch, thereby ensuring the stability and reliability of the clutch. By installing a speed sensor and a current sensor on the cutting motor on one side respectively, the speed signal and current signal of the cutting motor on one side can be collected in real time, and then the speed data and current data of the left cutting motor can be obtained. In this way, not only can the error be updated according to the load condition of the cutting motor, and the controller on the corresponding side can be adaptively gain adjusted to ensure that the power output can follow the load changes in real time, but also the controller can obtain the auxiliary torque required by the cutting motor on one side in real time, and then the auxiliary torque can be provided by controlling the engagement and disengagement of the electronically controlled clutch on the corresponding side to meet the requirements of the load condition. Furthermore, the distribution ratio of the auxiliary torque can be adjusted by calculating the speed difference between the left and right cutting motors to effectively balance the speed and load of the left and right cutting motors.

[0017] The system has a reasonable structure, good stability, and a high degree of intelligence. It has a sensitive response speed and can achieve dynamic management and smooth switching of auxiliary power, ensuring that the cutting system can effectively cope with various load changes. While reducing energy consumption, it effectively extends the service life of the coal mining machine.

[0018] The present invention also provides a control method for a coal mining machine dual-motor coupled hybrid cutting system, which uses a coal mining machine dual-motor coupled hybrid cutting system, comprising the following steps:

[0019] Step 1: When the coal mining machine starts to perform coal mining operations, the left cutting motor and the right cutting motor are controlled to start working synchronously, so that the coal mining machine enters a normal coal seam cutting working mode;

[0020] Step 2: The left current sensor is used to collect the current signal 1 of the left cutting motor in real time, and sends it to the controller; the left speed sensor is used to collect the speed signal 1 of the left cutting motor in real time, and sends it to the controller; the right current sensor is used to collect the current signal 2 of the right cutting motor in real time, and sends it to the controller; the right speed sensor is used to collect the speed signal 2 of the right cutting motor in real time, and sends it to the controller;

[0021] The controller obtains the current data of the left cutting motor according to the received current signal I and speed signal I 左 (t) and speed data -ω 左 (t), and then sense the load state of the left cutting motor in real time; the controller obtains the current data I of the right cutting motor according to the received current signal II and speed signal II 右 (t) and speed data ω 右 (t), and then sense the load state of the right cutting motor in real time;

[0022] Step 3: If the current data of the left cutting motor is I 左 (t) is greater than or equal to the overload current threshold I 阈值左 And the overload duration t 持续左 Greater than or equal to the duration threshold T 延时 , it is determined that the left cutting motor is overloaded, and step 4 is directly executed to enter the left cutting motor error update and adaptive gain adjustment process, otherwise, the left electromagnetic reversing valve is controlled to work in the middle position unchanged, so that the left hydraulic clutch is disengaged;

[0023] If the current data of the right cutting motor is I 右 (t) is greater than or equal to the overload current threshold I 阈值右 And the overload duration t 持续右 Greater than or equal to the duration threshold T 延时 , it is determined that the right cutting motor is overloaded, and step 4 is directly executed to enter the right cutting motor error update and adaptive gain adjustment process. Otherwise, the right electromagnetic reversing valve is controlled to work in the middle position unchanged, so that the right hydraulic clutch is disengaged;

[0024] Step 4: Update the real-time current error e(t) according to the motor load condition on the overload side, and adjust the control parameter on the overload side by adaptive gain θ(t) to ensure that the power output on the overload side can follow the load change on the overload side in real time;

[0025] S41: Obtain the real-time current error e(t) of the overload side motor according to formula (1), and perform error update according to the real-time current error e(t);

[0026] e(t)=I 实际 (t)-I 额定 (1);

[0027] In the formula, I 实际 (t) is the actual current at the current moment, I 额定 is the rated current of the motor;

[0028] S42: Define the Lyapunov function according to formula (2);

[0029]

[0030] In the formula, θ * is the ideal parameter value, γ>0 is the adaptive rate;

[0031] S43: Derivative the formula (2) to obtain the time rate of change of the Lyapunov function as shown in formula (3). At the same time,

[0032]

[0033] In the formula, is the adaptive parameter update law;

[0034] S44: Calculated according to formula (4) And use Update the adaptive gain θ(t);

[0035]

[0036] In the formula, is the regression vector;

[0037] S45: discretizing the adaptive gain using the Euler forward difference method according to formula (5);

[0038]

[0039] S46: setting the upper and lower limits of the adaptive gain θ(t) according to formula (6); when θ(t) exceeds the limit value, performing saturation processing to prevent the cutting system from becoming unstable;

[0040] 0≤θ(t)≤θ max (6);

[0041] Step 5: Calculate the auxiliary torque on the overload side according to the real-time load on the overload side, and obtain the required total input torque;

[0042] S51: Calculate the unilateral assist torque M using the updated adaptive gain θ(t) and the real-time current error e(t) according to formula (7) 辅助单侧 (t);

[0043] M 辅助单侧 (t) = -θ(t)·e(t) (7);

[0044] S52: Assist torque M according to formula (8) 辅助 (t) limit processing;

[0045] 0≤M 辅助 (t)≤M 辅助max (8);

[0046] S53: Use a first-order low-pass filter to filter the auxiliary torque M 辅助单侧 (t) is smoothed, and the smoothed assist torque M is obtained according to formula (9): 辅助滤波单侧 (t);

[0047] M 辅助滤波单侧 (t) = α·M 辅助单侧 (t)+(1-α)·M 辅助单侧 (t-Δt) (9);

[0048] S54: According to formula (10), the smoothed auxiliary torques on the left and right sides are added together to obtain the required total input torque M 总输入 ;

[0049] M 总输入 =M 辅助滤波左 +M 辅助滤波右 (10);

[0050] Step 6: Control the engagement and disengagement of the electronically controlled clutch through the electronically controlled reversing valve, so as to merge the auxiliary power with the output power of the cutting motor according to the actual situation, thereby realizing dynamic assistance to the cutting motor;

[0051] S61: Control the axial flux motor to start working and make the torque input to the active differential by the axial flux motor be M 总输入 ;

[0052] When the M on the corresponding side 辅助滤波When (t)>0, the controller controls the left motor to drive the left hydraulic pump to work, uses the oil discharge port of the left hydraulic pump to output high-pressure oil, and controls the left electromagnetic reversing valve to work in the left position or the right position, so that the left hydraulic clutch is engaged, and the auxiliary power output by the left output shaft of the active differential is input to an input end of the left torque synthesizer, and the left cutting drum is driven to perform cutting operation after the coupling effect of the left torque synthesizer and the power output by the left cutting motor are merged. Synchronously, the right motor is controlled to drive the right hydraulic pump to work, uses the oil discharge port of the right hydraulic pump to output high-pressure oil, and controls the right electromagnetic reversing valve to work in the left position or the right position accordingly, so that the right hydraulic clutch is engaged, and the auxiliary power output by the right output shaft of the active differential is input to an input end of the right torque synthesizer, and the left cutting drum is driven to perform cutting operation after the coupling effect of the right torque synthesizer and the power output by the right cutting motor are merged;

[0053] Synchronously, the output torque of the left cutting motor and the output torque of the right cutting motor are dynamically adjusted according to the allocated torque of the left cutting motor and the allocated torque of the right cutting motor, so that the speed of the cutting motor matches its load state. The specific process is as follows:

[0054] A1: Get the left cutting motor speed data in real time 左 (t) and the speed data of the right cutting motor ω 右 (t), and calculate the speed difference Δω(t) between the left cutting motor and the right cutting motor according to formula (11), and set the threshold ω by Δω(t) and the speed difference 阈值 For comparison, if |Δω(t)|>ω 阈值 , then execute A2, otherwise, the control keeps the output state of the active differential unchanged and directly executes A3;

[0055] Δω(t)=ω 左 (t)-ω 右 (t) (11);

[0056] A2: According to formula (12), the torque M required to be distributed to the left cutting motor is obtained. 输出分配左 (t), and then according to formula (13) the torque M required to be distributed to the right cutting motor is obtained 输出分配右 (t), the output torque of the left output shaft of the active differential is controlled to be M 输出分配左 (t), in order to balance the output of the left cutting motor, so that the speed of the left cutting motor and its load tend to be consistent, and control the output torque of the right output shaft of the active differential to M 输出分配右 (t) to balance the output of the right cutting motor so that the speed of the right cutting motor and its load tend to be consistent;

[0057]

[0058] M 输出分配右(t) = M 总输入 -M 输出分配左 (t) (13);

[0059] A3: According to the speed data of the left cutting motor 左 (t) Calculate the output torque M of the left cutting motor 电机左 (t), and then according to formula (14) the total output torque M on the left side is obtained 总左 (t), and for M 总左 (t) Perform kinetic analysis to ensure that M 总左 (t) not exceeding the load capacity of the left mechanical structure and the left cutting motor; according to the speed data of the right cutting motor 右 (t) Calculate the output torque M of the right cutting motor 电机右 (t), and then according to formula (15) the total output torque M on the right side is obtained 总右 (t), and M 总右 (t) Perform kinetic analysis to ensure that M 总右 (t) Exceeding the load capacity of the right mechanical structure and the right cutting motor

[0060] M 总左 (t) = M 电机左 (t)+M 输出分配左 (t) (14);

[0061] M 总右 (t) = M 电机右 (t)+M 输出分配右 (t) (15);

[0062] When M 辅助滤波 (t) When the pressure drops to zero or the overload state is released, the left electromagnetic reversing valve is controlled to operate in the middle position to disengage the left hydraulic clutch. At the same time, the right electromagnetic reversing valve is controlled to operate in the middle position to disengage the right hydraulic clutch, disconnecting the auxiliary torque output by the active differential and stopping the transmission process of the auxiliary power;

[0063] Step 7: Repeat steps 2 to 6 to dynamically adjust the distribution of the auxiliary torque.

[0064] In order to ensure the balance of the initial working state, in step one, the starting parameters of the left cutting motor and the right cutting motor are controlled to be completely consistent.

[0065] As a preferred embodiment, in step 2, the overload current threshold I is obtained according to formula (16): 阈值左 According to formula (17), the overload current threshold I is obtained 阈值右 ;

[0066] I 阈值左 =K 过载 ×I 额定左(16);

[0067] I 阈值右 =K 过载 ×I 额定右 (17);

[0068] In the formula, K 过载 is the overload factor, the value is 1.2; I 额定左 is the rated current of the left cutting motor, which is 0.5. 额定右 is the rated current of the right cutting motor, which takes a value of 0.5;

[0069] Furthermore, in order to accurately control the action of the electromagnetic reversing valve and make the action process of the electromagnetic reversing valve more stable, in step six, the controller uses PWM to control the action of the left electromagnetic reversing valve and the right electromagnetic reversing valve to ensure the smoothness and reliability of the reversing process of the left electromagnetic reversing valve and the right electromagnetic reversing valve.

[0070] The present invention proposes a new method for driving the electric-electric hybrid cutting part of a coal mining machine. First, it uses a current sensor to collect the current signal of the cutting motor in real time to obtain current data, and then compares the current data with the overload current threshold. When the current data exceeds the overload current threshold and reaches the overload duration, it determines that an overload has occurred, and then performs an error update and adaptive gain adjustment process. Through error update and adaptive gain adjustment, it can effectively ensure that the power output on the overload side can follow the changes in the load on the overload side in real time, thereby significantly improving the control accuracy and response speed, which is beneficial to the subsequent accurate auxiliary power distribution. Secondly, it calculates the required auxiliary torque based on the updated adaptive gain and current error, and can obtain the auxiliary torque required on one side. Then, through first-order filtering, the required auxiliary torque can be further accurately determined. On this basis, the auxiliary torque required on both sides is added to accurately determine the torque required to be input by the axial flux motor. In M 辅助滤波 When (t)>0, the electromagnetic reversing valve is controlled to switch to the engagement chamber, and the hydraulic clutch is gradually engaged, so that the auxiliary power output by the active differential can be transmitted to the cutting motor. The active differential and the hydraulic clutch work together to ensure that the torque distribution of the left and right cutting motors is always in the best state under different load conditions. When the auxiliary torque is reduced to zero or the overload state is released, the electromagnetic reversing valve switches to the separation chamber, and the hydraulic clutch can be disconnected immediately to stop the transmission of the auxiliary power. Through this process, mechanical shock can be effectively avoided and the smooth operation of the cutting system can be ensured. During the hydraulic clutch engagement process, the speed of the left and right cutting motors is used to control the active differential to dynamically distribute the auxiliary torque, which can make the torque adjustment process more flexible, effectively ensure that the speed of the cutting motor matches its load, and thus ensure the efficient operation of the coal mining machine. At the same time, the cutting motor can be effectively protected, which is conducive to extending the overall service life of the coal mining machine.

[0071] This method combines the output of the reasonably distributed auxiliary torque with the torque of the cutting motor, which can ensure that the coal mining machine can still maintain an efficient and stable working state under complex working conditions. At the same time, it can realize dynamic management and smooth switching of auxiliary power, ensuring that the cutting system can effectively cope with various load change conditions, which is conducive to reducing the maintenance cost of the coal mining machine and greatly improving the working efficiency and reliability of the coal mining machine. It has important practical significance and application value for promoting the advancement of coal mining technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 It is a principle block diagram of the cutting system in the present invention;

[0073] Figure 2 is a flow chart of the control method of the present invention;

[0074] Figure 3 It is a structural schematic diagram of the cutting system in the present invention.

[0075] In the figure: 1, axial flux motor, 2, active differential, 3, left electronically controlled clutch, 4, right electronically controlled clutch, 5, left torque synthesizer, 6, right torque synthesizer, 7, left cutting motor, 8, right cutting motor, 9, left motor, 10, left hydraulic pump, 11, left electromagnetic reversing valve, 12, left hydraulic clutch, 13, left clutch hydraulic cylinder one, 14, left clutch hydraulic cylinder two, 15, left working pressure valve, 16, left overflow valve, 17, hydraulic oil tank, 18, right motor, 19, right hydraulic pump, 20, right electromagnetic reversing valve, 21, right hydraulic clutch, 22, right clutch hydraulic cylinder one, 23, right clutch hydraulic cylinder two, 24, right working pressure valve, 25, right overflow valve. DETAILED DESCRIPTION

[0076] The present invention will be further described below in conjunction with the accompanying drawings.

[0077] like Figure 1 and Figure 3 As shown, the present invention provides a dual-motor coupled hybrid cutting system for a coal mining machine, comprising an axial flux motor 1, an active differential 2, a left electronically controlled clutch 3, a left cutting motor 7, a left torque synthesizer 5, a right electronically controlled clutch 4, a right cutting motor 8, a right torque synthesizer 6, a left sensor group, a right sensor group and a controller;

[0078] As a preferred embodiment, the axial flux motor 1 can be installed on a reduction box;

[0079] The output shaft of the axial flux motor 1 is connected to the input shaft of the active differential 2;

[0080] One input end of the left torque synthesizer 5 is connected to the left output shaft of the active differential 2 through the left electronically controlled clutch 3, and the other input end thereof is connected to the output shaft of the left cutting motor 7;

[0081] The left electronically controlled clutch 3 comprises a left hydraulic clutch 12, a left electromagnetic reversing valve 11, a left motor 9, a left working pressure valve 15, a left overflow valve 16 and a left hydraulic pump 10; the left hydraulic clutch 12 comprises a left clutch hydraulic cylinder 13 and a left clutch hydraulic cylinder 2 14; the left motor 9 is coaxially connected with the left hydraulic pump 10; the oil suction port of the left hydraulic pump 10 is connected with the hydraulic oil tank 17, and the oil discharge port output of the left hydraulic pump 10 is divided into two paths, one of which is connected with the P port of the left electromagnetic reversing valve 11 through a pipeline, and the other is connected with the P port of the left electromagnetic reversing valve 11 through a pipeline. The left working pressure valve 15 is connected to the oil inlet through a pipeline; the oil outlet of the left working pressure valve 15 is divided into two routes, one route is respectively connected to the rod chamber of the left clutch hydraulic cylinder 13 and the rod chamber of the left clutch hydraulic cylinder 2 14, and the other route is connected to the hydraulic oil tank 17 through the left overflow valve 16; the T port of the left electromagnetic reversing valve 11 is connected to the hydraulic oil tank 17 through a pipeline, the A port thereof is connected to the rodless chamber of the left clutch hydraulic cylinder 13 through a pipeline, and the B port thereof is connected to the rodless chamber of the left clutch hydraulic cylinder 2 14 through a pipeline;

[0082] One input end of the right torque synthesizer 6 is connected to the right output shaft of the active differential 2 through the right electronically controlled clutch 4, and the other input end thereof is connected to the output shaft of the right cutting motor 8;

[0083] The right electronically controlled clutch 4 comprises a right hydraulic clutch 21, a right electromagnetic reversing valve 20, a right motor 18, a right working pressure valve 24, a right overflow valve 25 and a right hydraulic pump 19; the right hydraulic clutch 21 comprises a right clutch hydraulic cylinder 1 22 and a right clutch hydraulic cylinder 2 23; the right motor 18 is coaxially connected to the right hydraulic pump 19; the oil suction port of the right hydraulic pump 19 is connected to the hydraulic oil tank 17, and the oil discharge port output of the right hydraulic pump 19 is divided into two paths, one of which is connected to the P port of the right electromagnetic reversing valve 20 through a pipeline, and the other is connected to the P port of the right electromagnetic reversing valve 20 through a pipeline. One path is connected to the oil inlet of the right working pressure valve 24; the oil outlet of the right working pressure valve 24 is divided into two paths, one path is connected to the rod chamber of the right clutch hydraulic cylinder 1 22 and the rod chamber of the right clutch hydraulic cylinder 2 23 respectively, and the other path is connected to the hydraulic oil tank 17 through the right overflow valve 25; the T port of the right electromagnetic reversing valve 20 is connected to the hydraulic oil tank 17 through a pipeline, its A port is connected to the rodless chamber of the right clutch hydraulic cylinder 1 22 through a pipeline, and its B port is connected to the rodless chamber of the right clutch hydraulic cylinder 2 23 through a pipeline.

[0084] The left sensor group includes a left current sensor and a left speed sensor; the left current sensor is connected to the left cutting motor 7 and is used to collect the current signal of the left cutting motor 7 in real time; the left speed sensor is connected to the left cutting motor 7 and is used to collect the speed signal of the left cutting motor 7 in real time;

[0085] The right sensor group includes a right current sensor and a right speed sensor; the right current sensor is connected to the right cutting motor 8 and is used to collect the current signal 2 of the right cutting motor 8 in real time; the right speed sensor is connected to the right cutting motor 8 and is used to collect the speed signal 2 of the right cutting motor 8 in real time;

[0086] As a preferred embodiment, the sampling frequency of the left sensor group and the right sensor group is set to 1000Hz to meet the real-time requirements of the control, wherein the analog signals collected by the sensors are successively subjected to filtering and anti-interference processing, which can ensure the accuracy and stability of the signals and help the controller obtain accurate monitoring data;

[0087] The controller is respectively connected to the left sensor group, the right sensor group, the active differential 2, the left cutting motor 7, the left electromagnetic reversing valve 11, the left motor 9, the right electromagnetic reversing valve 20, the right motor 18 and the right cutting motor 8.

[0088] As a preference, the controller is a PLC controller.

[0089] As a preferred embodiment, the left solenoid reversing valve 11 and the right solenoid reversing valve 20 are both three-position four-way solenoid reversing valves. When they work in the left position, the oil circuit between their P port and A port is connected, and the oil circuit between their T port and B port is connected. When they work in the middle position, their P port is cut off, and their T port, A port and B port are connected to each other. When they work in the right position, the oil circuit between their P port and B port is connected, and the oil circuit between their T port and A port is connected.

[0090] In the present invention, the output shaft of the axial flux motor is connected to the input shaft of the active differential, and the left output shaft and the right output shaft of the active differential are respectively output to the left cutting system and the right cutting system, which can provide additional driving force for the left cutting system and the right cutting system. Since the axial flux motor has the advantages of compact structure, high power density, high efficiency, etc., it is suitable for providing stable driving force in a limited space. In this way, by adding an axial flux motor, a stable additional driving force can be provided for the cutting system, so as to effectively deal with the situation where the left cutting motor is overloaded and the right cutting motor is overloaded, which can ensure the stable and reliable cutting operation of the coal mining machine and can be conducive to improving the coal mining efficiency. The unilateral output shaft of the active differential is connected to an input end of the unilateral torque synthesizer through a unilateral electronically controlled clutch, and at the same time, the other input end of the unilateral torque synthesizer is connected to the output shaft of the unilateral cutting motor. In this way, the output of the unilateral cutting motor and the unilateral output of the active differential can be efficiently coupled by using the unilateral torque synthesizer, and then the total output after coupling can be used to efficiently drive the unilateral cutting drum to perform cutting operations. At the same time, the control of the engagement and disengagement of the unilateral electronically controlled clutch can be achieved by controlling the unilateral electromagnetic reversing valve, and then the connection or disengagement process of the additional driving force can be conveniently controlled according to the load requirements, and the dynamic management and smooth switching of the auxiliary power can be achieved, ensuring that the cutting system can effectively cope with various load change conditions. The unilateral hydraulic clutch is provided with clutch hydraulic cylinders one and two at the same time, and the clutch hydraulic cylinders one and two are respectively connected to the A port and the B port of the unidirectional electromagnetic reversing valve. When one clutch hydraulic cylinder fails, the other clutch hydraulic cylinder can still be used to ensure the normal operation of the clutch, thereby ensuring the stability and reliability of the clutch. By installing a speed sensor and a current sensor on the cutting motor on one side respectively, the speed signal and current signal of the cutting motor on one side can be collected in real time, and then the speed data and current data of the left cutting motor can be obtained. In this way, not only can the error be updated according to the load condition of the cutting motor, and the controller on the corresponding side can be adaptively gain adjusted to ensure that the power output can follow the load changes in real time, but also the controller can obtain the auxiliary torque required by the cutting motor on one side in real time, and then the auxiliary torque can be provided by controlling the engagement and disengagement of the electronically controlled clutch on the corresponding side to meet the requirements of the load condition. Furthermore, the distribution ratio of the auxiliary torque can be adjusted by calculating the speed difference between the left and right cutting motors to effectively balance the speed and load of the left and right cutting motors.

[0091] The system has a reasonable structure, good stability, and a high degree of intelligence. It has a sensitive response speed and can achieve dynamic management and smooth switching of auxiliary power, ensuring that the cutting system can effectively cope with various load changes. While reducing energy consumption, it effectively extends the service life of the coal mining machine.

[0092] like Figure 2 As shown, the present invention also provides a control method for a coal mining machine dual-motor coupled hybrid cutting system, using a coal mining machine dual-motor coupled hybrid cutting system, comprising the following steps:

[0093] Step 1: When the coal mining machine starts to perform coal mining operations, the left cutting motor 7 and the right cutting motor 8 are controlled to start working synchronously, so that the coal mining machine enters a normal coal seam cutting working mode;

[0094] Step 2: The current signal 1 of the left cutting motor 7 is collected in real time by the left current sensor, and sent to the controller; the speed signal 1 of the left cutting motor 7 is collected in real time by the left speed sensor, and sent to the controller; the current signal 2 of the right cutting motor 8 is collected in real time by the right current sensor, and sent to the controller; the speed signal 2 of the right cutting motor 8 is collected in real time by the right speed sensor, and sent to the controller;

[0095] The controller obtains the current data I of the left cutting motor 7 according to the received current signal I and speed signal I 左 (t) and speed data -ω 左 (t), and then sense the load state of the left cutting motor 7 in real time; the controller obtains the current data of the right cutting motor 8 according to the received current signal 2 and speed signal 2 I 右 (t) and speed data ω 右 (t), and then sense the load state of the right cutting motor 8 in real time;

[0096] Step 3: If the current data of the left cutting motor 7 is I 左 (t) is greater than or equal to the overload current threshold I 阈值左 And the overload duration t 持续左 Greater than or equal to the duration threshold T 延时 , it is determined that the left cutting motor 7 is overloaded, and step 4 is directly executed to enter the error update and adaptive gain adjustment process of the left cutting motor 7. Otherwise, the left electromagnetic reversing valve 11 is controlled to work in the neutral position unchanged, so that the left hydraulic clutch 12 is disengaged;

[0097] If the current data of the right cutting motor 8 is equal to I 右 (t) is greater than or equal to the overload current threshold I 阈值右 And the overload duration t 持续右 Greater than or equal to the duration threshold T 延时 , it is determined that the right cutting motor 8 is overloaded, and step 4 is directly executed to enter the error update and adaptive gain adjustment process of the right cutting motor 8. Otherwise, the right electromagnetic reversing valve 20 is controlled to work in the neutral position unchanged, so that the right hydraulic clutch 21 is disengaged;

[0098] Step 4: Update the real-time current error e(t) according to the motor load condition on the overload side, and adjust the control parameter on the overload side by adaptive gain θ(t) to ensure that the power output on the overload side can follow the load change on the overload side in real time;

[0099] S41: Obtain the real-time current error e(t) of the overload side motor according to formula (1), and perform error update according to the real-time current error e(t);

[0100] e(t)=I 实际 (t)-I 额定 (1);

[0101] In the formula, I 实际 (t) is the actual current at the current moment, I 额定 is the rated current of the motor;

[0102] S42: Define the Lyapunov function according to formula (2);

[0103]

[0104] In the formula, θ * is the ideal parameter value, γ>0 is the adaptive rate;

[0105] S43: Derivative the formula (2) to obtain the time rate of change of the Lyapunov function as shown in formula (3). At the same time,

[0106]

[0107] In the formula, is the adaptive parameter update law;

[0108] S44: Calculated according to formula (4) And use Update the adaptive gain θ(t);

[0109]

[0110] In the formula, is the regression vector;

[0111] S45: discretizing the adaptive gain using the Euler forward difference method according to formula (5);

[0112]

[0113] S46: setting the upper and lower limits of the adaptive gain θ(t) according to formula (6); when θ(t) exceeds the limit value, performing saturation processing to prevent the cutting system from becoming unstable;

[0114] 0≤θ(t)≤θ max (6);

[0115] Step 5: Calculate the auxiliary torque on the overload side according to the real-time load on the overload side, and obtain the required total input torque;

[0116] S51: Calculate the unilateral assist torque M using the updated adaptive gain θ(t) and the real-time current error e(t) according to formula (7) 辅助单侧 (t);

[0117] M 辅助单侧 (t) = -θ(t)·e(t) (7);

[0118] S52: To prevent the control input from being too large, torque limiting is performed, and the auxiliary torque M is calculated according to formula (8). 辅助 (t) limit processing;

[0119] 0≤M 辅助 (t)≤M 辅助max (8);

[0120] S53: Use a first-order low-pass filter to filter the auxiliary torque M 辅助单侧 (t) is smoothed, and the smoothed assist torque M is obtained according to formula (9): 辅助滤波单侧 (t);

[0121] M 辅助滤波单侧 (t) = α·M 辅助单侧 (t)+(1-α)·M 辅助单侧 (t-Δt) (9);

[0122] S54: According to formula (10), the smoothed auxiliary torques on the left and right sides are added together to obtain the required total input torque M 总输入 ;

[0123] M 总输入 =M 辅助滤波左 +M 辅助滤波右 (10);

[0124] Among them, M 辅助滤波左 and M 辅助滤波右 All are calculated by formula (9);

[0125] Step 6: Control the engagement and disengagement of the electronically controlled clutch through the electronically controlled reversing valve, so as to merge the auxiliary power with the output power of the cutting motor according to the actual situation, thereby realizing dynamic assistance to the cutting motor;

[0126] S61: Control the axial flux motor 1 to start working, and make the torque input by the axial flux motor 1 to the active differential 2 be M 总输入; When the M on the corresponding side 辅助滤波 When (t)>0, the controller controls the left motor 9 to drive the left hydraulic pump 10 to work, and uses the oil discharge port of the left hydraulic pump 10 to output high-pressure oil, and controls the left electromagnetic reversing valve 11 to work in the left position or the right position, so that the left hydraulic clutch 12 is engaged, and the auxiliary power output by the left output shaft of the active differential 2 is input to an input end of the left torque synthesizer 5, and after the coupling effect of the left torque synthesizer 5 and the power output by the left cutting motor 7 are merged, the left cutting drum is driven to perform cutting operation. Synchronously, the right motor 18 is controlled to drive the right hydraulic pump 19 to work, and the oil discharge port of the right hydraulic pump 19 is used to output high-pressure oil, and the right electromagnetic reversing valve 20 is controlled to work in the left position or the right position accordingly, so that the right hydraulic clutch 21 is engaged, and the auxiliary power output by the right output shaft of the active differential 2 is input to an input end of the right torque synthesizer 6, and after the coupling effect of the right torque synthesizer 6 and the power output by the right cutting motor 8 are merged, the left cutting drum is driven to perform cutting operation;

[0127] Synchronously, the output torque of the left cutting motor 7 and the output torque of the right cutting motor 8 are dynamically adjusted according to the allocated torque of the left cutting motor 7 and the allocated torque of the right cutting motor 8, so that the rotation speed of the cutting motor matches its load state. The specific process is as follows:

[0128] A1: Real-time acquisition of the speed data of the left cutting motor 7 左 (t) and the speed data of the right cutting motor 8 右 (t), and calculate the speed difference Δω(t) between the left cutting motor 7 and the right cutting motor 8 according to formula (11), and set the threshold value ω by Δω(t) and the speed difference 阈值 For comparison, if |Δω(t)|>ω 阈值 , then execute A2, otherwise, the control keeps the output state of the active differential 2 unchanged and directly executes A3;

[0129] Δω(t)=ω 左 (t)-ω 右 (t) (11);

[0130] A2: According to formula (12), the torque M required to be distributed to the left cutting motor 7 is obtained. 输出分配左 (t), and then according to formula (13) the torque M required to be distributed to the right cutting motor 8 is obtained 输出分配右 (t), control the output torque of the left output shaft of the active differential 2 to be M 输出分配左 (t), to balance the output of the left cutting motor 7, so that the speed of the left cutting motor 7 and its load tend to be consistent, and control the output torque of the right output shaft of the active differential 2 to be M 输出分配右 (t), to balance the output of the right cutting motor 8 so that the speed of the right cutting motor 8 and its load tend to be consistent;

[0131]

[0132] M 输出分配右 (t) = M 总输入 -M 输出分配左 (t) (13);

[0133] A3: According to the speed data of the left cutting motor 7 左 (t) Calculate the output torque M of the left cutting motor 7 电机左 (t), and then according to formula (14) the total output torque M on the left side is obtained 总左 (t), and for M 总左 (t) Perform kinetic analysis to ensure that M 总左 (t) does not exceed the load capacity of the left mechanical structure and the left cutting motor 7; according to the speed data of the right cutting motor 8 右 (t) Calculate the output torque M of the right cutting motor 8 电机右 (t), and then according to formula (15) the total output torque M on the right side is obtained 总右 (t), and M 总右 (t) Perform kinetic analysis to ensure that M 总右 (t) Exceeding the load capacity of the right mechanical structure and the right cutting motor 8

[0134] M 总左 (t) = M 电机左 (t)+M 输出分配左 (t) (14);

[0135] M 总右 (t) = M 电机右 (t)+M 输出分配右 (t) (15);

[0136] When M 辅助滤波 (t) When the pressure drops to zero or the overload state is released, the left electromagnetic reversing valve 11 is controlled to work in the middle position to disengage the left hydraulic clutch 12. At the same time, the right electromagnetic reversing valve 20 is controlled to work in the middle position to disengage the right hydraulic clutch 21, disconnecting the auxiliary torque output by the active differential 2 and stopping the transmission process of the auxiliary power;

[0137] Step 7: Repeat steps 2 to 6 to dynamically adjust the distribution of the auxiliary torque.

[0138] In order to ensure the balance of the initial working state, in step one, the starting parameters of the left cutting motor 7 and the right cutting motor 8 are controlled to be completely consistent.

[0139] As a preferred embodiment, in step 2, the overload current threshold I is obtained according to formula (16): 阈值左 According to formula (17), the overload current threshold I is obtained阈值右 ;

[0140] I 阈值左 =K 过载 ×I 额定左 (16);

[0141] I 阈值右 =K 过载 ×I 额定右 (17);

[0142] In the formula, K 过载 is the overload factor, the value is 1.2; I 额定左 is the rated current of the left cutting motor 7, which is 0.5, I 额定右 is the rated current of the right cutting motor 8, which takes a value of 0.5;

[0143] In order to accurately control the action of the electromagnetic reversing valve and make the action process of the electromagnetic reversing valve more stable, in step six, the controller uses PWM to control the action of the left electromagnetic reversing valve 11 and the right electromagnetic reversing valve 20 to ensure the smoothness and reliability of the reversing process of the left electromagnetic reversing valve 11 and the right electromagnetic reversing valve 20.

[0144] The present invention proposes a new method for driving the electric-electric hybrid cutting part of a coal mining machine. First, it uses a current sensor to collect the current signal of the cutting motor in real time to obtain current data, and then compares the current data with the overload current threshold. When the current data exceeds the overload current threshold and reaches the overload duration, it determines that an overload has occurred, and then performs an error update and adaptive gain adjustment process. Through error update and adaptive gain adjustment, it can effectively ensure that the power output on the overload side can follow the changes in the load on the overload side in real time, thereby significantly improving the control accuracy and response speed, which is beneficial to the subsequent accurate auxiliary power distribution. Secondly, it calculates the required auxiliary torque based on the updated adaptive gain and current error, and can obtain the auxiliary torque required on one side. Then, through first-order filtering, the required auxiliary torque can be further accurately determined. On this basis, the auxiliary torque required on both sides is added to accurately determine the torque required to be input by the axial flux motor. In M 辅助滤波When (t)>0, the electromagnetic reversing valve is controlled to switch to the engagement chamber, and the hydraulic clutch is gradually engaged, so that the auxiliary power output by the active differential can be transmitted to the cutting motor. The active differential and the hydraulic clutch work together to ensure that the torque distribution of the left and right cutting motors is always in the best state under different load conditions. When the auxiliary torque is reduced to zero or the overload state is released, the electromagnetic reversing valve switches to the separation chamber, and the hydraulic clutch can be disconnected immediately to stop the transmission of the auxiliary power. Through this process, mechanical shock can be effectively avoided and the smooth operation of the cutting system can be ensured. During the hydraulic clutch engagement process, the speed of the left and right cutting motors is used to control the active differential to dynamically distribute the auxiliary torque, which can make the torque adjustment process more flexible, effectively ensure that the speed of the cutting motor matches its load, and thus ensure the efficient operation of the coal mining machine. At the same time, the cutting motor can be effectively protected, which is conducive to extending the overall service life of the coal mining machine.

[0145] This method combines the output of the reasonably distributed auxiliary torque with the torque of the cutting motor, which can ensure that the coal mining machine can still maintain an efficient and stable working state under complex working conditions. At the same time, it can realize dynamic management and smooth switching of auxiliary power, ensuring that the cutting system can effectively cope with various load change conditions, which is conducive to reducing the maintenance cost of the coal mining machine and greatly improving the working efficiency and reliability of the coal mining machine. It has important practical significance and application value for promoting the advancement of coal mining technology.

Claims

1. A dual-motor coupled hybrid cutting system for a coal mining machine, comprising an axial flux motor (1), characterized in that: It also includes an active differential (2), a left electronically controlled clutch (3), a left cutting motor (7), a left torque synthesizer (5), a right electronically controlled clutch (4), a right cutting motor (8), a right torque synthesizer (6), a left sensor group, a right sensor group and a controller; The output shaft of the axial flux motor (1) is connected to the input shaft of the active differential (2); One input end of the left torque synthesizer (5) is connected to the left output shaft of the active differential (2) through the left electronically controlled clutch (3), and the other input end is connected to the output shaft of the left cutting motor (7); The left electronically controlled clutch (3) comprises a left hydraulic clutch (12), a left electromagnetic reversing valve (11), a left motor (9), a left working pressure valve (15), a left overflow valve (16) and a left hydraulic pump (10); the left hydraulic clutch (12) comprises a left clutch hydraulic cylinder 1 (13) and a left clutch hydraulic cylinder 2 (14); the left motor (9) is coaxially connected to the left hydraulic pump (10); the oil suction port of the left hydraulic pump (10) is connected to the hydraulic oil tank (17), and the oil discharge port output of the left hydraulic pump (10) is divided into two paths, one of which is connected to the P of the left electromagnetic reversing valve (11) through a pipeline. The left working pressure valve (15) has an oil outlet connected to the left clutch hydraulic cylinder (13) and the left clutch hydraulic cylinder (14), and the other is connected to the oil inlet of the left working pressure valve (15); the oil outlet of the left working pressure valve (15) is divided into two ways, one of which is respectively connected to the rod chamber of the left clutch hydraulic cylinder (13) and the rod chamber of the left clutch hydraulic cylinder (14), and the other is connected to the hydraulic oil tank (17) through the left overflow valve (16); the T port of the left electromagnetic reversing valve (11) is connected to the hydraulic oil tank (17) through a pipeline, the A port thereof is connected to the rodless chamber of the left clutch hydraulic cylinder (13) through a pipeline, and the B port thereof is connected to the rodless chamber of the left clutch hydraulic cylinder (14) through a pipeline; One input end of the right torque synthesizer (6) is connected to the right output shaft of the active differential (2) through the right electronically controlled clutch (4), and the other input end is connected to the output shaft of the right cutting motor (8); The right electronically controlled clutch (4) comprises a right hydraulic clutch (21), a right electromagnetic reversing valve (20), a right motor (18), a right working pressure valve (24), a right overflow valve (25) and a right hydraulic pump (19); the right hydraulic clutch (21) comprises a right clutch hydraulic cylinder 1 (22) and a right clutch hydraulic cylinder 2 (23); the right motor (18) is coaxially connected to the right hydraulic pump (19); the oil suction port of the right hydraulic pump (19) is connected to the hydraulic oil tank (17), and the oil discharge port output of the right hydraulic pump (19) is divided into two paths, one of which is connected to the right electromagnetic reversing valve (20) through a pipeline. The right solenoid reversing valve (20) is connected to the hydraulic oil tank (17) through a pipeline, and its A port is connected to the rodless chamber of the right clutch hydraulic cylinder (22) through a pipeline, and its B port is connected to the rodless chamber of the right clutch hydraulic cylinder (23) through a pipeline. The left sensor group comprises a left current sensor and a left rotation speed sensor; the left current sensor is connected to the left cutting motor (7) and is used to collect a current signal of the left cutting motor (7) in real time; the left rotation speed sensor is connected to the left cutting motor (7) and is used to collect a rotation speed signal of the left cutting motor (7) in real time; The right sensor group comprises a right current sensor and a right rotation speed sensor; the right current sensor is connected to the right cutting motor (8) and is used to collect the second current signal of the right cutting motor (8) in real time; the right rotation speed sensor is connected to the right cutting motor (8) and is used to collect the second rotation speed signal of the right cutting motor (8) in real time; The controller is respectively connected to the left sensor group, the right sensor group, the active differential (2), the left cutting motor (7), the left electromagnetic reversing valve (11), the left motor (9), the right electromagnetic reversing valve (20), the right motor (18) and the right cutting motor (8).

2. A coal mining machine dual-motor coupled hybrid cutting system according to claim 1, characterized in that: The controller is a PLC controller.

3. A coal mining machine dual-motor coupled hybrid cutting system according to claim 2, characterized in that: The left electromagnetic reversing valve (11) and the right electromagnetic reversing valve (20) are both three-position four-way electromagnetic reversing valves. When they are working in the left position, the oil circuit between their P port and A port is connected, and the oil circuit between their T port and B port is connected. When they are working in the middle position, their P port is cut off, and their T port, A port and B port are connected to each other. When they are working in the right position, the oil circuit between their P port and B port is connected, and the oil circuit between their T port and A port is connected.

4. A control method for a coal mining machine dual-motor coupled hybrid cutting system, using a coal mining machine dual-motor coupled hybrid cutting system as claimed in any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: When the coal mining machine starts to perform coal mining operations, the left cutting motor (7) and the right cutting motor (8) are controlled to start working synchronously, so that the coal mining machine enters a normal coal seam cutting working mode; Step 2: collecting a current signal 1 of the left cutting motor (7) in real time through the left current sensor and sending it to the controller; collecting a speed signal 1 of the left cutting motor (7) in real time through the left speed sensor and sending it to the controller; collecting a current signal 2 of the right cutting motor (8) in real time through the right current sensor and sending it to the controller; collecting a speed signal 2 of the right cutting motor (8) in real time through the right speed sensor and sending it to the controller; The controller obtains the current data I of the left cutting motor (7) according to the received current signal I and speed signal I 左 (t) and speed data -ω 左 (t), and then sense the load state of the left cutting motor (7) in real time; the controller obtains the current data I of the right cutting motor (8) according to the received current signal II and speed signal II 右 (t) and speed data ω 右 (t), and then sense the load state of the right cutting motor (8) in real time; Step 3: If the current data of the left cutting motor (7) is I 左 (t) is greater than or equal to the overload current threshold I 阈值左 And the overload duration t 持续左 Greater than or equal to the duration threshold T 延时 , it is determined that the left cutting motor (7) is overloaded, and step 4 is directly executed to enter the error update and adaptive gain adjustment process of the left cutting motor (7); otherwise, the left electromagnetic reversing valve (11) is controlled to work in the neutral position unchanged, so that the left hydraulic clutch (12) is disengaged; If the current data of the right cutting motor (8) is 右 (t) is greater than or equal to the overload current threshold I 阈值右 And the overload duration t 持续右 Greater than or equal to the duration threshold T 延时 , it is determined that the right cutting motor (8) is overloaded, and step 4 is directly executed to enter the error update and adaptive gain adjustment process of the right cutting motor (8); otherwise, the right electromagnetic reversing valve (20) is controlled to work in the neutral position unchanged, so that the right hydraulic clutch (21) is disengaged; Step 4: Update the real-time current error e(t) according to the motor load condition on the overload side, and adjust the control parameter on the overload side by adaptive gain θ(t) to ensure that the power output on the overload side can follow the load change on the overload side in real time; S41: Obtain the real-time current error e(t) of the overload side motor according to formula (1), and perform error update according to the real-time current error e(t); e(t)=I 实际 (t)-I 额定 (1); In the formula, I 实际 (t) is the actual current at the current moment, I 额定 is the rated current of the motor; S42: Define the Lyapunov function according to formula (2); In the formula, θ * is the ideal parameter value, γ>0 is the adaptive rate; S43: Derivative the formula (2) to obtain the time rate of change of the Lyapunov function as shown in formula (3). At the same time, In the formula, is the adaptive parameter update law; S44: Calculated according to formula (4) And use Update the adaptive gain θ(t); In the formula, is the regression vector; S45: discretizing the adaptive gain using the Euler forward difference method according to formula (5); S46: setting the upper and lower limits of the adaptive gain θ(t) according to formula (6); when θ(t) exceeds the limit value, performing saturation processing to prevent the cutting system from becoming unstable; 0≤θ(t)≤θ max (6); Step 5: Calculate the auxiliary torque on the overload side according to the real-time load on the overload side, and obtain the required total input torque; S51: Calculate the unilateral assist torque M using the updated adaptive gain θ(t) and the real-time current error e(t) according to formula (7) 辅助单侧 (t); M 辅助单侧 (t)=-θ(t)·e(t) (7); S52: Assist torque M according to formula (8) 辅助 (t) limit processing; 0≤M 辅助单侧 (t)≤M 辅助max (8); S53: Use a first-order low-pass filter to filter the auxiliary torque M 辅助单侧 (t) is smoothed, and the smoothed assist torque M is obtained according to formula (9): 辅助滤波单侧 (t); M 辅助滤波单侧 (t)=α·M 辅助单侧 (t)+(1-α)·M 辅助单侧 (t-Δt) (9); S54: According to formula (10), the smoothed auxiliary torques on the left and right sides are added together to obtain the required total input torque M 总输入 ; M 总输入 =M 辅助滤波左 +M 辅助滤波右 (10); Step 6: Control the engagement and disengagement of the electronically controlled clutch through the electronically controlled reversing valve, so as to merge the auxiliary power with the output power of the cutting motor according to the actual situation, thereby realizing dynamic assistance to the cutting motor; S61: Control the axial flux motor (1) to start working, and make the torque input from the axial flux motor (1) to the active differential (2) be M 总输入 ; When the M on the corresponding side 辅助滤波 When (t)>0, the controller controls the left motor (9) to drive the left hydraulic pump (10) to work, uses the oil discharge port of the left hydraulic pump (10) to output high-pressure oil, and controls the left electromagnetic reversing valve (11) to work in the left position or the right position, so that the left hydraulic clutch (12) is engaged, and the auxiliary power output by the left output shaft of the active differential (2) is input to an input end of the left torque synthesizer (5), and after the coupling effect of the left torque synthesizer (5) and the power output by the left cutting motor (7) are merged, the left cutting drum is driven to perform cutting. The right motor (18) is synchronously controlled to drive the right hydraulic pump (19) to work, and the high-pressure oil is outputted through the oil discharge port of the right hydraulic pump (19), and the right electromagnetic reversing valve (20) is controlled to work in the left position or the right position accordingly, so that the right hydraulic clutch (21) is engaged, and the auxiliary power outputted by the right output shaft of the active differential (2) is inputted into an input end of the right torque synthesizer (6), and the power outputted by the right cutting motor (8) is combined through the coupling effect of the right torque synthesizer (6) to drive the left cutting drum to perform cutting operation; Synchronously, the output torque of the left cutting motor (7) and the output torque of the right cutting motor (8) are dynamically adjusted according to the distributed torque of the left cutting motor (7) and the distributed torque of the right cutting motor (8), so that the rotation speed of the cutting motor matches its load state. The specific process is as follows: A1: Real-time acquisition of the speed data of the left cutting motor (7) 左 (t) and the speed data of the right cutting motor (8) 右 (t), and calculate the speed difference Δω(t) between the left cutting motor (7) and the right cutting motor (8) according to formula (11), and set the threshold value ω by Δω(t) and the speed difference 阈值 For comparison, if |Δω(t)|>ω 阈值 , then execute A2, otherwise, the control keeps the output state of the active differential (2) unchanged and directly executes A3; Dω(t)=ω 左 (t)-ω 右 (t) (11); A2: According to formula (12), the torque M required to be distributed to the left cutting motor (7) is obtained. 输出分配左 (t), and then according to formula (13) the torque M required to be distributed to the right cutting motor (8) is obtained 输出分配右 (t), the output torque of the left output shaft of the active differential (2) is controlled to be M 输出分配左 (t), in order to balance the output of the left cutting motor (7), so that the speed of the left cutting motor (7) and its load tend to be consistent, and control the output torque of the right output shaft of the active differential (2) to be M 输出分配右 (t) to balance the output of the right cutting motor (8) so that the speed of the right cutting motor (8) and its load tend to be consistent; M 输出分配右 (t)=M 总输入 -M 输出分配左 (t) (13); A3: According to the speed data of the left cutting motor (7) 左 (t) Calculate the output torque M of the left cutting motor (7) 电机左 (t), and then according to formula (14) the total output torque M on the left side is obtained 总左 (t), and for M 总左 (t) Perform kinetic analysis to ensure that M 总左 (t) does not exceed the load-bearing capacity of the left mechanical structure and the left cutting motor (7); according to the speed data of the right cutting motor (8) 右 (t) Calculate the output torque M of the right cutting motor (8) 电机右 (t), and then according to formula (15) the total output torque M on the right side is obtained 总右 (t), and M 总右 (t) Perform kinetic analysis to ensure that M 总右 (t) Exceeding the load capacity of the right mechanical structure and the right cutting motor (8) M 总左 (t)=M 电机左 (t)+M 输出分配左 (t) (14); M 总右 (t)=M 电机右 (t)+M 输出分配右 (t) (15); When M 辅助滤波 (t) when the pressure is reduced to zero or the overload state is released, the left electromagnetic reversing valve (11) is controlled to operate in the middle position, so that the left hydraulic clutch (12) is disengaged, and at the same time, the right electromagnetic reversing valve (20) is controlled to operate in the middle position, so that the right hydraulic clutch (21) is disengaged, the auxiliary torque output by the active differential (2) is disconnected, and the transmission process of the auxiliary power is stopped; Step 7: Repeat steps 2 to 6 to dynamically adjust the distribution of the auxiliary torque.

5. The control method of the dual-motor coupled hybrid cutting system of a coal mining machine according to claim 4 is characterized in that: In step one, the starting parameters of the left cutting motor (7) and the right cutting motor (8) are controlled to be completely consistent.

6. The control method of the dual-motor coupled hybrid cutting system of a coal mining machine according to claim 5, characterized in that: In step 2, the overload current threshold I is obtained according to formula (16): 阈值左 According to formula (17), the overload current threshold I is obtained 阈值右 ; I 阈值左 =K 过载× I 额定左 (16); I 阈值右 =K 过载 ×I 额定右 (17); In the formula, K 过载 is the overload factor, the value is 1.2; I 额定左 is the rated current of the left cutting motor (7), which is 0.5, I 额定右 is the rated current of the right cutting motor (8), which takes a value of 0.

5.

7. A control method for a dual-motor coupled hybrid cutting system for a coal mining machine according to claim 6, characterized in that: In step six, the controller uses PWM to control the actions of the left electromagnetic reversing valve (11) and the right electromagnetic reversing valve (20) to ensure the stability and reliability of the reversing process of the left electromagnetic reversing valve (11) and the right electromagnetic reversing valve (20).

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