A blood pump control system and control method

Abstract

The present invention provides a blood pump control system and a control method. The blood pump control system includes a variable power supply module, a driving module, a control module, an inductive motor and a detection module; the variable power supply module is connected to the driving module and the control module, and provides a variable driving voltage to the driving module; the driving module is connected to the inductive motor to drive the inductive motor; the control module is connected to the driving module, outputs a PWM signal to the driving module to drive the inductive motor, and adjusts the driving voltage supplied by the variable power supply module to the driving module; the detection module is connected to the inductive motor and the control module, and feeds back the detected load current and speed of the inductive motor to the control module; the control method includes: the control module obtains the load current fed back by the inductive motor; the working state of the inductive motor is judged according to the load current; and the control mode of the inductive motor is set according to the working state of the inductive motor. The present invention realizes stable control of the speed of the inductive motor under various working states.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a blood pump control system and a control method. Background Art

[0002] The motors currently used in blood pumps generally use high-speed motors with small size (less than 6mm in diameter) and very low inductance. The actual working conditions of this type of motor are very complex. It may need to be used in purified water or air during production in a clean workshop, it may be used in physiological saline or simulated blood, and it may also be used in patients with heart failure. Since blood pumps are sterile medical devices, motor assembly or pump production must be carried out in a clean workshop, and the entire test must minimize contact with the sterile environment, so the motor or blood pump speed is often tested in the air at no load to see if it is qualified.

[0003] The brushless DC motor is a type of brushless DC motor (BLDC) that lacks direct speed feedback. Its square wave control method is designed based on the motor's back electromotive force, and the control accuracy is closely related to the detection accuracy of the motor's back electromotive force. The self-inductance of the micro-inductive motor coil used for the blood pump is very small. When working under light load conditions, the back electromotive force signal is weak and unstable, which will cause detection errors and ultimately cause the motor speed to jitter. Several typical motor jitter situations under working conditions are as follows: Figure 1 and Figure 2 As shown below: Under no-load conditions, if the motor rotates directly in the air, the motor speed will be as follows: Figure 1 The jitter shown in the figure is frequent. Under light load, if the pump head is placed in saline, the load is greatly increased compared to air, and the motor speed jitter is reduced, but not completely eliminated. Figure 2 Under heavy load, such as cardiac pressurization simulation platform or after implantation in human body, due to the high pressure at the outlet of pump head, the motor load increases linearly at the same speed, and there will be no jitter due to small back electromotive force.

[0004] Therefore, it is necessary to design a blood pump control system and control method to solve the above problems. Summary of the invention

[0005] The technical problem solved by the embodiments of the present invention mainly lies in setting a variable power supply module to realize the regulation and control of the driving voltage of the driving module, confirming the working state of the inductive motor through the load current, selecting the control method of the inductive motor according to the working state of the inductive motor, and realizing the stable control of the rotation speed of the inductive motor under various working states.

[0006] In order to solve the above technical problems, an embodiment of the present invention provides a blood pump control system. The blood pump control system includes a variable power supply module, a drive module, a control module, an inductive motor and a detection module;

[0007] The variable power supply module is connected to the driving module and the control module to supply power to the control module and provide a variable driving voltage to the driving module;

[0008] The driving module is connected to the inductive motor to drive the inductive motor to rotate;

[0009] The control module is connected to the driving module, outputs a PWM signal to the driving module to drive the inductive motor, and adjusts the driving voltage supplied by the variable power supply module to the driving module;

[0010] The detection module is connected to the inductorless motor and the control module, and feeds back the detected load current and speed of the inductorless motor to the control module;

[0011] The control module, the variable power module, the drive module and the detection module form a current closed-loop control loop. The control module adjusts the drive voltage supplied by the variable power module to the drive module according to the difference between the set working current and the load current fed back by the detection module, so that the current of the inductive motor is stabilized at the working current.

[0012] The control module, the drive module and the detection module form a speed closed-loop control circuit. The control module adjusts the duty cycle of the PWM signal output to the drive module according to the difference between the set working speed and the speed fed back by the detection module, so that the speed of the inductive motor is stabilized at the working speed.

[0013] Based on the same concept, an embodiment of the present invention further provides a control method for a blood pump, which adopts the above-mentioned blood pump control system, and the blood pump control system includes a variable power supply module, a driving module, a control module, an inductive motor and a detection module; the variable power supply module is connected to the driving module and the control module to supply power to the control module and provide a variable driving voltage to the driving module; the driving module is connected to the inductive motor to drive the inductive motor to rotate; the control module is connected to the driving module, outputs a PWM signal to the driving module to drive the inductive motor, and adjusts the driving voltage supplied by the variable power supply module to the driving module; the detection module is connected to the inductive motor and the control module, and feeds back the detected load current and speed of the inductive motor to the control module; the control method includes the following steps:

[0014] The control module obtains the load current of the inductive motor fed back by the detection module;

[0015] Determine the working state of the inductive motor according to the magnitude of the load current, wherein the working state of the inductive motor includes a no-load state, a light-load state and a heavy-load state;

[0016] According to the working state of the sensorless motor, set the control parameters and control mode of the sensorless motor;

[0017] If the inductive motor is operating in a no-load state or a light-load state, the inductive motor is controlled to adopt a double closed-loop control of current control and speed control according to the set operating current and operating speed;

[0018] If the inductive motor operates in a heavy-load state, the inductive motor is controlled to adopt a single-speed closed-loop control with a single-speed control according to the set operating speed and driving voltage.

[0019] Optionally, the dual closed-loop control of current control and speed control includes: adjusting the driving voltage supplied by the variable power supply module to the driving module according to the difference between the preset working current and the load current fed back by the detection module, so that the current of the inductive motor is stabilized at the working current; adjusting the duty cycle of the PWM signal output to the driving module under the changing driving voltage, so that the speed of the inductive motor is stabilized at the working speed.

[0020] Optionally, the single-speed closed-loop control of the single-speed control includes: under a set driving voltage, the control module adjusts the duty cycle of the PWM signal output to the driving module so that the current of the inductive motor is stabilized at the operating speed.

[0021] Optionally, the driving voltage set by the single-speed closed-loop control is the maximum voltage of the variable power module.

[0022] Optionally, judging the working state of the inductorless motor according to the load current includes:

[0023] If the load current is less than the first current limit value, it is determined that the inductorless motor is in a no-load state;

[0024] If the load current is greater than or equal to the first current limit value and less than the second current limit value, it is determined that the inductorless motor is in a light load state; wherein the second current limit value is greater than the first current limit value, and the first current limit value and the second current limit value are pre-set thresholds;

[0025] If the load current is greater than or equal to the second current limit value, it is determined that the inductorless motor is in a heavy load state.

[0026] Optionally, the inductive motor operates in a no-load state or a light-load state. According to the set working current and working speed, the control module controls the driving module to adopt a dual closed-loop control of current control and speed control, and adjusts the driving voltage supplied by the variable power supply module to the driving module according to the working current, so that the current of the inductive motor is stabilized at the working current, including: obtaining the driving voltage through PI adjustment according to the difference between the load current fed back by the detection module and the working current, and the driving voltage is calculated by the following formula:

[0027] I err =I ref -I fbk

[0028]

[0029] Among them, K Ip and K Ii are the proportional and integral parameters of the current control PI regulation; I err is the current deviation; I ref is the set working current; I fbk is the load current fed back by the detection module; U k is the driving voltage at time k; is the current deviation at time k; is the current deviation at a certain moment before time k.

[0030] Optionally, the inductive motor operates in a no-load state or a light-load state. According to the set operating current and operating speed, the control module controls the driving module to adopt a dual closed-loop control of current control and speed control, and adjusts the duty cycle of the PWM signal output to the driving module so that the speed of the inductive motor is stabilized at the operating speed, including: obtaining the duty cycle of the PWM signal through PI adjustment according to the difference between the speed feedback from the detection module and the operating speed, and the duty cycle of the PWM signal is calculated by the following formula:

[0031] V err =V ref -V fbk

[0032]

[0033] Among them, K Vp and K Vi are the proportional and integral parameters of the speed control PI adjustment respectively; V err is the speed deviation; V ref is the set working speed; V fbk The speed fed back by the detection module; PWM kis the duty cycle of the PWM signal at time k; is the speed deviation at time k; is the speed deviation at a certain moment before time k.

[0034] Optionally, an initial setting is performed before the control module obtains the load current fed back by the inductive motor, and the inductive motor is driven to operate with the initial setting. The initial setting includes: setting the initial driving voltage supplied by the variable power supply module to the driving module; setting the initial duty cycle of the PWM signal output by the control module to the driving module; setting the operating speed and operating current when no-load or light-loaded; setting the operating speed and driving voltage when heavily loaded; and setting a first current limit value and a second current limit value.

[0035] Based on the same concept, the present invention also provides a medical device, which at least includes the above-mentioned blood pump control system and blood pump.

[0036] Based on the same concept, the present invention also provides a computer program product for executing the above blood pump control method.

[0037] Based on the same concept, the present invention also provides a computer-readable storage medium for storing the above-mentioned computer program product.

[0038] Compared with the prior art, the technical solution of the embodiment of the present invention has beneficial effects.

[0039] For example, the blood pump control system and control method of the present invention are provided with a variable power supply module and a detection module; the variable power supply module is connected to the driving module to provide a variable driving voltage to the driving module; the control module is connected to the driving module, outputs a PWM signal to the driving module to drive the inductive motor, and adjusts the driving voltage supplied by the variable power supply module to the driving module, thereby realizing the regulation and control of the driving voltage of the driving module; the detection module is connected to the inductive motor and the control module, and feeds back the detected load current and speed of the inductive motor to the control module, and the working state of the inductive motor can be confirmed by the load current, and the control method of the inductive motor can be selected according to the working state of the inductive motor, thereby realizing the stable control of the speed of the inductive motor under various working states.

[0040] For example, in the no-load or light-load state, the load current is maintained at the set operating current by adjusting the driving voltage of the driving module, avoiding the situation where the back electromotive force signal is weak and unstable when the load is small under a constant large driving voltage, resulting in back electromotive force detection errors and ultimately causing speed jitter of the inductive motor; at the same time, by adjusting the duty cycle of the PWM signal, stable speed control is achieved under a variable driving voltage, and stable and reliable control of the operating current and operating speed is achieved.

[0041] For example, under heavy load conditions, the load current is large, the back electromotive force signal is strong, and the detection error of the back electromotive force is small. There is no need to control the working current. By setting the driving voltage of the driving module, the driving voltage can be kept constant at a relatively high state, which is beneficial to the stable operation of the inductive motor under heavy load conditions. By adjusting the duty cycle of the PWM signal under a constant relatively high driving voltage, stable speed control can be achieved, and the control method is stable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a motor speed diagram of the existing blood pump motor when it is unloaded;

[0043] Figure 2 It is a motor speed diagram of the existing blood pump motor under light load;

[0044] Figure 3 is an architectural diagram of a blood pump system in an embodiment of the present invention;

[0045] Figure 4 is a flow chart of a blood pump control method according to an embodiment of the present invention;

[0046] Figure 5 This is a current control block diagram of the inductive motor when it is unloaded or lightly loaded in an embodiment of the present invention;

[0047] Figure 6 This is a speed control block diagram of the inductive motor when it is unloaded or lightly loaded in an embodiment of the present invention;

[0048] Figure 7 This is a block diagram of the speed control of the inductive motor under heavy load in an embodiment of the present invention;

[0049] Figure 8 It is a detailed flow chart of the blood pump control method in an embodiment of the present invention.

[0050] In the figure:

[0051] 1. Variable power supply module; 2. Drive module; 3. Control module; 4. Inductive motor; 5. Detection module; 51. Current detection unit; 52. Speed ​​detection unit. DETAILED DESCRIPTION

[0052] In order to make the purpose, features and beneficial effects of the present invention more obvious and understandable, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It is understood that the specific embodiments described below are only used to explain the present invention, rather than to limit the present invention. In addition, the same or similar reference numerals may be used in the figures to refer to the same or similar elements in different embodiments, and the description of the same or similar elements in different embodiments and the description of the prior art elements, features, effects, etc. may be omitted.

[0053] Reference Figure 3, an embodiment of the present invention provides a blood pump control system.

[0054] Specifically, the blood pump control system includes a variable power supply module 1, a drive module 2, a control module 3, an inductive motor 4 and a detection module 5;

[0055] The variable power supply module 1 is connected to the driving module 2 and the control module 3 to supply power to the control module 3 and provide a variable driving voltage to the driving module 2;

[0056] The driving module 2 is connected to the inductive motor 4 to drive the inductive motor 4 to rotate;

[0057] The control module 3 is connected to the driving module 2, outputs a PWM signal to the driving module 2 to drive the inductive motor 4, and adjusts the driving voltage supplied by the variable power module 1 to the driving module 2;

[0058] The detection module 5 is connected to the inductive motor 4 and the control module 3. The detection module 5 includes a current detection unit 51 and a speed detection unit 52, which are respectively used to detect the load current and speed of the inductive motor 4. The detection module 5 feeds back the detected load current and speed of the inductive motor 4 to the control module 3.

[0059] The control module 3, the variable power module 1, the drive module 2 and the detection module 5 form a current closed-loop control circuit. The control module 3 adjusts the drive voltage supplied by the variable power module 1 to the drive module 2 according to the difference between the set working current and the load current fed back by the detection module 5, so that the current of the inductive motor 4 is stabilized at the working current;

[0060] The control module 3, the drive module 2 and the detection module 5 form a speed closed-loop control circuit. The control module 3 adjusts the duty cycle of the PWM signal output to the drive module 2 according to the difference between the set working speed and the speed feedback from the detection module, so that the speed of the inductive motor 4 is stabilized at the working speed.

[0061] Based on the principle of conservation of motor work, when the motor is in a certain working condition, the power consumption is certain; according to P=U*I, when P is small, that is, the load is small, if the voltage U is large, the current I is small, and thus the back electromotive force is small, and the back electromotive force detection error is large; therefore, in the case of no-load or light load (P is small), by dynamically reducing the value of the voltage U, thereby increasing the current I, the back electromotive force increases accordingly, and ultimately eliminating the motor speed jitter caused by the back electromotive force detection error.

[0062] Reference Figure 3-Figure 7The embodiment of the present invention also provides a control method for a blood pump, which adopts a blood pump control system, including a variable power supply module 1, a driving module 2, a control module 3, an inductive motor 4 and a detection module 5; the variable power supply module 1 is connected to the driving module 2 and the control module 3 to supply power to the control module 3 and provide a variable driving voltage to the driving module 2; the driving module 2 is connected to the inductive motor 4 to drive the inductive motor 4 to rotate; the control module 3 is connected to the driving module 2, outputs a PWM signal to the driving module 2 to drive the inductive motor 4, and adjusts the driving voltage supplied by the variable power supply module 1 to the driving module 2; the detection module 5 is connected to the inductive motor 4 and the control module 3, and feeds back the detected load current and speed of the inductive motor 4 to the control module 3;

[0063] Control methods such as Figure 4 As shown, the following steps are included:

[0064] S101: The control module 3 obtains the load current of the inductive motor 4 fed back by the detection module 5;

[0065] S102: judging the working state of the inductive motor 4 according to the magnitude of the load current, the working state of the inductive motor 4 including a no-load state, a light-load state and a heavy-load state;

[0066] S103: According to the working state of the inductive motor 4, the control parameters and control mode of the inductive motor 4 are set: if the inductive motor 4 is working in a no-load state or a light-load state, the inductive motor 4 is controlled to adopt a dual closed-loop control of current control and speed control according to the set working current and working speed; if the inductive motor 4 is working in a heavy-load state, the inductive motor 4 is controlled to adopt a single-speed closed-loop control of single-speed control according to the set working speed and driving voltage.

[0067] In some embodiments, the dual closed-loop control of current control and speed control includes: adjusting the driving voltage supplied by the variable power supply module 1 to the driving module 2 according to the difference between the preset working current and the load current fed back by the detection module 5, so that the current of the inductive motor 4 is stabilized at the working current; adjusting the duty cycle of the PWM signal output to the driving module 2 under the changing driving voltage, so that the speed of the inductive motor 4 is stabilized at the working speed. In the prior art, the single speed control only controls the motor speed, and the dual-loop control of current and speed only adjusts the duty cycle of the PWM signal; the present invention adopts the dual closed-loop control of current control and speed control, and adjusts the duty cycle and driving voltage of the PWM signal at the same time, so that the control is more accurate and stable.

[0068] In some embodiments, the single-speed closed-loop control of the single-speed control includes: under a preset driving voltage, the control module 3 adjusts the duty cycle of the PWM signal output to the driving module 2 so that the current of the inductive motor 4 is stabilized at the operating speed.

[0069] In a specific implementation, in a heavy load state, the preset driving voltage is the maximum voltage of the variable power module to facilitate driving a large load.

[0070] In some embodiments, determining the working state of the inductive motor according to the load current includes:

[0071] If the load current is less than the first current limit value, it is determined that the inductorless motor 4 is in a no-load state;

[0072] If the load current is greater than or equal to the first current limit value and less than the second current limit value, it is determined that the inductorless motor 4 is in a light load state; the second current limit value is greater than the first current limit value, and the first current limit value and the second current limit value are thresholds set according to specific circumstances;

[0073] If the load current is greater than or equal to the second current limit value, it is determined that the inductorless motor 4 is in a heavy load state.

[0074] In a specific embodiment, the first current limit value is 10 mA, and the second current limit value is 100 mA.

[0075] See also Figure 5 In some embodiments, the control module 3 performs initial settings before obtaining the load current fed back by the inductive motor 4, and drives the inductive motor 4 to operate with the initial settings. The initial settings include: setting the initial driving voltage supplied by the variable power module 1 to the driving module 2; setting the initial duty cycle of the PWM signal output by the control module 3 to the driving module 2; setting the operating speed and operating current when no load or light load; setting the operating speed and driving voltage when heavy load; setting the first current limit value and the second current limit value. See the parameter adjustment table in Table 1 below for details:

[0076] Table 1 Parameter adjustment table

[0077]

[0078]

[0079] In a specific implementation, the initial driving voltage is 40%-60% of the maximum voltage of the variable power module 1; and the initial duty cycle is 50%-60%.

[0080] In some embodiments, the inductive motor 4 operates in a no-load state or a light-load state. According to a preset working current and working speed, the control module 3 controls the driving module 2 to adopt a double closed-loop control of current control and speed control:

[0081] like Figure 3 and Figure 5As shown, the current control of the dual closed-loop control includes: adjusting the driving voltage supplied by the variable power module 1 to the driving module 2 according to the working current, so that the current of the inductive motor 4 is stabilized at the working current, specifically including: according to the difference between the load current and the working current fed back by the current detection unit 51 of the detection module 5, the control module 3 performs PI (Proportional-Integral) adjustment to obtain the driving voltage U, and the variable power control module 1 outputs the driving voltage U to the driving module 2 to control the inductive motor 4 to operate at the driving voltage U. The driving voltage is calculated by the following formula:

[0082] I err =I ref -I fbk

[0083]

[0084] Among them, K Ip and K Ii are the proportional and integral parameters of the current control PI regulation; I err is the current deviation; I ref is the set working current; I fbk The load current fed back by the detection module 5 is detected; U k is the driving voltage U at time k; is the current deviation at time k; is the current deviation at a certain moment before time k.

[0085] In a specific implementation, the working current and working speed in the no-load state may be different from the working current and working speed in the light-load state, and the working current and working speed in the no-load state may be pre-stored in the control module 3.

[0086] The inductive motor 4 works in a no-load state or a light-load state. According to the set working current and working speed, the control module 3 controls the driving module 2 to adopt a double closed-loop control of current control and speed control:

[0087] like Figure 3 and Figure 6As shown, the speed control of the dual closed-loop control includes: adjusting the duty cycle of the PWM signal output to the driving module 2 so that the speed of the inductive motor 4 is stabilized at the working speed, specifically including: according to the difference between the speed feedback from the speed detection unit 52 of the detection module 5 and the working speed, the duty cycle PWM of the PWM signal is obtained by PI adjustment through the control module 3, the duty cycle PWM is output to the driving module 2 through the control module 3, and the driving voltage U adjusted by the control module 3 is applied to the driving module 2 through the variable power supply control module 1 to control the inductive motor 4 to operate with the duty cycle PWM. The duty cycle of the PWM signal is calculated by the following formula:

[0088] V err =V ref -V fbk

[0089]

[0090] Among them, K Vp and K Vi are the proportional and integral parameters of the speed control PI adjustment respectively; V err is the speed deviation; V ref is the set working speed; V fbk The speed feedback from the detection module 5; PWM k is the duty cycle of the PWM signal at time k; is the speed deviation at time k; is the speed deviation at a certain moment before time k.

[0091] Under no-load or light-load conditions, a dual-loop control system is used, where the current loop and speed loop work simultaneously and independently to adjust the motor current and motor speed respectively. The control loop parameters and initial output settings for different load conditions are shown in the parameter adjustment table in Table 1 above.

[0092] like Figure 3 and Figure 7 As shown, in some embodiments, the inductive motor 4 works in a heavy-load state, the load current is large, the back electromotive force signal is strong, the detection error of the back electromotive force is small, and there is no need to control the working current. By setting the driving voltage of the driving module 2, the driving voltage is kept constant at a large state, which is conducive to the operation of the inductive motor 4 in a heavy-load state. In other words, the inductive motor 4 works in a heavy-load state, and the speed is stably controlled by adjusting the duty cycle of the PWM signal under a constant large driving voltage. The control method is stable and reliable, that is, according to the set working speed and driving voltage, the inductive motor 4 is controlled to adopt a single-speed closed-loop control with a single speed control:

[0093] U k =U max

[0094] V err =V ref -V fbk

[0095]

[0096] Under the set driving voltage, according to the difference between the speed feedback from the speed detection unit 52 of the detection module 5 and the working speed, the duty cycle PWM of the PWM signal is obtained by PI adjustment through the control module 3, and the duty cycle PWM is output to the driving module 2 through the control module 3, and a fixed driving voltage is applied to the driving module 2 through the variable power supply control module 1 to control the inductive motor 4 to operate with the duty cycle PWM. The control module adjusts the duty cycle of the PWM signal output to the driving module so that the current of the inductive motor is stabilized at the working speed. Specifically, the set driving voltage is the maximum voltage Umax of the variable power supply module.

[0097] See also Figure 8 In the specific implementation, the initial setting is first performed to set the parameters of the motor under various load working conditions, and then the load current, i.e., the feedback current value, is measured. According to the magnitude of the load current, the actual working state of the motor is determined to be no-load, light-loaded, or heavy-loaded. Specifically, if the load current is less than the first current limit value (e.g., 10mA), the inductive motor 4 is determined to be in a no-load state; if the load current is greater than or equal to the first current limit value and less than the second current limit value (e.g., 100mA), the inductive motor 4 is determined to be in a light-loaded state; if the load current is greater than or equal to the second current limit value, the inductive motor 4 is determined to be in a heavy-loaded state. Then, according to the working state query table 1 parameter adjustment table, the control parameters and adjustment means corresponding to the working state load conditions are obtained, and single-speed closed-loop control or dual closed-loop control with current control and speed control is performed. Specifically, when it is determined that the inductive motor 4 is working in a no-load state, according to the parameter adjustment table in Table 1 above, a dual closed-loop control mode of current control and speed control is adopted, and the variable driving voltage U and the variable duty cycle PWM obtained by PI adjustment are input to the driving module 2, so that the inductive motor 4 maintains a stable speed in the no-load working state; when it is determined that the inductive motor 4 is working in a light-load state, according to the parameter adjustment table in Table 1 above, a dual closed-loop control mode of current control and speed control is adopted, and the variable driving voltage U and the variable duty cycle PWM obtained by PI adjustment are input to the driving module 2, so that the inductive motor 4 maintains a stable speed in the light-load working state; when it is determined that the inductive motor 4 is working in a heavy-load state, according to the parameter adjustment table in Table 1 above, a single-speed closed-loop control with single speed control is adopted, and a fixed driving voltage Umax and a variable duty cycle PWM are input to the driving module 2, so that the inductive motor 4 maintains a stable speed in the heavy-load working state.

[0098] In summary, the blood pump control system and control method of the present invention are provided with a variable power supply module 1 and a detection module 5; the variable power supply module 1 is connected to the driving module 2 to provide a variable driving voltage to the driving module 2; the control module 3 is connected to the driving module 2, outputs a PWM signal to the driving module 2 to drive the inductive motor 4, and adjusts the driving voltage supplied by the variable power supply module 1 to the driving module 2, so as to realize the regulation and control of the driving voltage of the driving module 2; the detection module 5 is connected to the inductive motor 4 and the control module 3, and feeds back the detected load current and speed of the inductive motor 4 to the control module 3, and the working state of the inductive motor 4 can be confirmed by the load current, and the control method of the inductive motor 4 can be selected according to the working state of the inductive motor 4, so as to realize the stable control of the speed of the inductive motor 4 under various working states.

[0099] Furthermore, in the no-load or light-load state, the present invention adjusts the driving voltage of the driving module 2 so that the load current is maintained at the set working current, thereby avoiding the situation where the load current is small and the back electromotive force signal is weak and unstable when the load is small under a constant large driving voltage, resulting in back electromotive force detection errors and ultimately causing the speed jitter of the inductive motor 4; at the same time, by adjusting the duty cycle of the PWM signal, stable speed control is achieved under a variable driving voltage, and stable and reliable control of the working current and working speed is achieved.

[0100] Furthermore, in the present invention, under a heavy load state, the load current is large, the back electromotive force signal is strong, the detection error of the back electromotive force is small, and there is no need to control the working current. By setting the driving voltage of the driving module 2, the driving voltage is kept constant at a relatively large state, which is beneficial to the operation of the inductive motor 4 under a heavy load state. By adjusting the duty cycle of the PWM signal under a constant relatively large driving voltage, stable speed control is achieved, and the control method is stable and reliable.

[0101] Although specific embodiments have been described above, these embodiments are not intended to limit the scope of the present disclosure, even when only a single embodiment is described with respect to specific features. The feature examples provided in the present disclosure are intended to be illustrative rather than limiting, unless otherwise stated. In specific implementations, the technical features of one or more dependent claims may be combined with the technical features of the independent claim, based on actual needs and where technically feasible, and may be derived from the technical features of the corresponding independent claim in any appropriate manner rather than simply through the specific combination listed in the claims.

[0102] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A blood pump control method, characterized in that: The control module is powered by a variable power supply module, and a variable driving voltage is provided to the driving module; the inductive motor is driven to rotate by the driving module; the control module outputs a PWM signal to the driving module to drive the inductive motor, and adjusts the driving voltage supplied by the variable power supply module to the driving module; The load current and speed of the inductorless motor are detected by a detection module, and the detected load current and speed of the inductorless motor are fed back to the control module; the control method comprises the following steps: the control module obtains the load current of the inductorless motor fed back by the detection module; Determine the working state of the inductive motor according to the magnitude of the load current, wherein the working state of the inductive motor includes a no-load state, a light-load state and a heavy-load state; According to the working state of the sensorless motor, set the control parameters and control mode of the sensorless motor; If the inductive motor is operating in a no-load state or a light-load state, the inductive motor is controlled to adopt a double closed-loop control of current control and speed control according to the set operating current and operating speed; The current control of the dual closed-loop control includes: adjusting the driving voltage supplied by the variable power supply module to the driving module according to the difference between the preset working current and the load current fed back by the detection module, so that the current of the inductive motor is stabilized at the working current; the speed control of the dual closed-loop control includes: adjusting the duty cycle of the PWM signal output to the driving module under the changing driving voltage, so that the speed of the inductive motor is stabilized at the working speed; If the inductive motor operates in a heavy-load state, the inductive motor is controlled to adopt a single-speed closed-loop control with a single-speed control according to the set operating speed and driving voltage.

2. The blood pump control method according to claim 1, characterized in that: The single speed closed loop control of the single speed control includes: under a set driving voltage, the control module adjusts the duty cycle of the PWM signal output to the driving module so that the speed of the inductive motor is stabilized at the working speed.

3. The blood pump control method according to claim 2, characterized in that: The set driving voltage is the maximum voltage of the variable power module.

4. The blood pump control method according to claim 1, characterized in that: Judging the working state of the inductive motor according to the load current includes: If the load current is less than the first current limit value, it is determined that the inductorless motor is in a no-load state; If the load current is greater than or equal to the first current limit value and less than the second current limit value, and the second current limit value is greater than the first current limit value, it is determined that the inductorless motor is in a light load state; wherein the first current limit value and the second current limit value are preset thresholds; If the load current is greater than or equal to the second current limit value, it is determined that the inductorless motor is in a heavy load state.

5. The blood pump control method according to claim 1, characterized in that: The inductive motor operates in a no-load state or a light-load state. According to the set working current and working speed, the control module controls the driving module to adopt a double closed-loop control of current control and speed control, and adjusts the driving voltage supplied by the variable power supply module to the driving module according to the working current, so that the current of the inductive motor is stabilized at the working current, including: obtaining the driving voltage through PI adjustment according to the difference between the load current fed back by the detection module and the working current, and the driving voltage is calculated by the following formula: I err =I ref -I fbk Among them, K Ip and K Ii are the proportional and integral parameters of the current control PI regulation; I err is the current deviation; I ref is the set working current; I fbk is the load current fed back by the detection module; U k is the driving voltage at time k; is the current deviation at time k; is the current deviation at a certain moment before time k.

6. The blood pump control method according to claim 1, characterized in that: The inductive motor operates in a no-load state or a light-load state. According to the set operating current and operating speed, the control module controls the driving module to adopt a dual closed-loop control of current control and speed control, and adjusts the duty cycle of the PWM signal output to the driving module so that the speed of the inductive motor is stabilized at the operating speed, including: obtaining the duty cycle of the PWM signal through PI adjustment according to the difference between the speed feedback from the detection module and the operating speed, and the duty cycle of the PWM signal is calculated by the following formula: V err =V ref -V fbk Among them, K Vp and K Vi are the proportional and integral parameters of the speed control PI adjustment respectively; V err is the speed deviation; V ref is the set working speed; V fbk The speed fed back by the detection module; PWM k is the duty cycle of the PWM signal at time k; is the speed deviation at time k; is the speed deviation at a certain moment before time k.

7. The blood pump control method according to claim 4, characterized in that: Before the control module obtains the load current fed back by the inductive motor, an initial setting is performed to drive the inductive motor to operate, and the initial setting includes: setting the initial driving voltage supplied by the variable power supply module to the driving module; setting the initial duty cycle of the PWM signal output by the control module to the driving module; setting the operating speed and operating current when no-load or light-loaded; setting the operating speed and driving voltage when heavily loaded; and setting a first current limit value and a second current limit value.

8. A blood pump control system, characterized in that: Used to execute the blood pump control method according to any one of claims 1 to 7, the blood pump control system comprising a variable power supply module, a drive module, a control module, an inductive motor and a detection module; The variable power supply module is connected to the driving module and the control module to supply power to the control module and provide a variable driving voltage to the driving module; The driving module is connected to the inductive motor to drive the inductive motor to rotate; the control module is connected to the driving module, outputs a PWM signal to the driving module to drive the inductive motor, and adjusts the driving voltage supplied by the variable power supply module to the driving module; The detection module is connected to the inductorless motor and the control module, and feeds back the detected load current and speed of the inductorless motor to the control module; The control module, the variable power module, the drive module and the detection module form a current closed-loop control loop. The control module adjusts the drive voltage supplied by the variable power module to the drive module according to the difference between the set working current and the load current fed back by the detection module, so that the current of the inductive motor is stabilized at the working current. The control module, the drive module and the detection module form a speed closed-loop control circuit. The control module adjusts the duty cycle of the PWM signal output to the drive module according to the difference between the set working speed and the speed fed back by the detection module, so that the speed of the inductive motor is stabilized at the working speed.

9. A medical device, characterized in that: At least comprises a blood pump control system and a blood pump as claimed in claim 8.

10. A computer program product, characterized in that Used to execute the blood pump control method as described in any one of claims 1-7.

11. A computer-readable storage medium, characterized in that: For storing the computer program product as claimed in claim 10.

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