Rotating speed control method and device for breathing machine turbine

Abstract

The invention discloses a rotating speed control method and device for a breathing machine turbine, and relates to the technical field of medical equipment. The method comprises the following steps: acquiring a stator current actual component and a phase voltage component of a breathing machine turbine; inputting the stator current actual component and the phase voltage component into a sliding mode observer to obtain a rotor angle of the breathing machine turbine; the target treatment pressure required by the patient and the actual pressure of the breathing machine turbine are obtained, and the target rotating speed of the breathing machine turbine is obtained; and controlling the rotating speed of the breathing machine turbine to be the target rotating speed based on the rotor angle and the FOC control mode. The turbine rotor angle is obtained through the sliding film observer, Hall-free control of the turbine can be achieved, the influence of turbine parameters is small, the parameters are easy to adjust, control is stable, and development efficiency is improved. And meanwhile, the high reliability is achieved, the turbine can output more stable flow and pressure, and the comfort and the treatment effect of the breathing machine are improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of medical equipment, and in particular to a method and device for controlling the rotation speed of a ventilator turbine. Background Art

[0002] A ventilator turbine usually refers to the part of the turbine inside a ventilator that is used to provide airflow and regulate pressure. A ventilator is a medical device that is widely used to assist or replace a patient's natural breathing, especially during a serious illness or recovery after surgery. The ventilator's turbine can effectively push air or oxygen through the patient's airway to ensure that they receive an adequate oxygen supply and help remove carbon dioxide.

[0003] The turbine control in the ventilator will have a Hall sensor. When driving the turbine, the angle detected by the Hall sensor is used for 6-step commutation control or magnetic field oriented control of the turbine. This method usually uses 3 Hall sensors to detect the 6 angles of the motor, with a difference of 60 degrees between each angle. However, this will cause torque pulsation when the turbine motor is commutated, introducing unnecessary vibration and noise. In addition, this turbine drive method is highly dependent on the Hall signal. In practical applications, the Hall element is the most easily damaged component in the turbofan. At the same time, the Hall signal is easily disturbed by the outside world and generates noise, resulting in turbine commutation failure, causing the turbine to stop or even damage. Therefore, there is an urgent need for a new method to control the speed of the ventilator turbine. Summary of the invention

[0004] The purpose of this application is to solve at least one of the above-mentioned technical deficiencies.

[0005] On the one hand, an embodiment of the present application provides a method for controlling the speed of a ventilator turbine, the method comprising:

[0006] Obtaining actual components of stator current and phase voltage components of the ventilator turbine;

[0007] The actual component of the stator current and the phase voltage component are input into the sliding mode observer to obtain the rotor angle of the ventilator turbine;

[0008] Obtain the target treatment pressure required by the patient and the actual pressure of the ventilator turbine, and obtain the target speed of the ventilator turbine;

[0009] The speed of the ventilator turbine is controlled to the target speed based on the rotor angle and FOC control method.

[0010] Optionally, the actual component of the stator current and the voltage information are input into the sliding mode observer to obtain the rotor angle of the ventilator turbine, including:

[0011] Obtaining an equation of a sliding mode observer, and inputting the actual component of the stator current and the phase voltage component into the equation of the sliding mode observer to obtain an estimated back electromotive force;

[0012] Based on the estimated back EMF, the rotor angle of the ventilator turbine is obtained.

[0013] Alternatively, the equations for the sliding mode observer are obtained as follows:

[0014] Obtain the voltage equation of the surface-mounted permanent magnet synchronous motor in the ventilator in a two-phase stationary coordinate system;

[0015] According to the voltage equation, the equation of sliding mode observer is established;

[0016] The equation for the sliding mode observer is as follows:

[0017]

[0018] in, and is the estimated component of stator current, and is the difference between the estimated component of stator current and the actual component of stator current, u α and u β is the phase voltage component, L s is the stator inductance, and R is the stator resistance.

[0019] Optionally, the actual component of the stator current and the phase voltage component are input into the equation of the sliding mode observer to obtain the estimated back EMF, including:

[0020] Based on the actual component of the stator current, the phase voltage component and the equation of the sliding mode observer, an error representation of the estimated value of the stator current is determined;

[0021] Obtaining sliding surface parameter values ​​and sliding surface representation expressions;

[0022] Based on defining sliding surface parameter values, defining a sliding surface representation expression, and an estimation value error representation expression, an estimated back electromotive force is obtained.

[0023] Optionally, the estimated back EMF is expressed as:

[0024]

[0025] in, and To estimate the back EMF, and is the difference between the estimated component of the stator current and the actual component of the stator current, and K is the adjustment parameter.

[0026] Optionally, based on the estimated back electromotive force, the rotor angle of the ventilator turbine is obtained, including:

[0027] Perform low-pass filtering on the estimated back electromotive force to obtain a target back electromotive force; obtain the angular velocity and the low-pass filter cutoff frequency of the surface-mounted permanent magnet synchronous motor, and process the target back electromotive force according to the angular velocity and the low-pass filter cutoff frequency to obtain a rotor angle; or,

[0028] The initial stator angle value is obtained, and the sine and cosine values ​​of the initial stator angle value are multiplied by the estimated back electromotive force to obtain a product value; the product value is input into the first PI controller for iterative processing until the error of the first PI regulator meets the requirements to obtain an estimated angular velocity; the estimated angular velocity is integrated to obtain the rotor angle.

[0029] Optionally, the target back EMF is processed according to the angular velocity and the low-pass filter cutoff frequency to obtain the rotor angle, including:

[0030] Performing inverse tangent processing on the target back EMF to obtain the estimated rotor angle;

[0031] According to the angular velocity and the cutoff frequency of the low-pass filter, the compensated rotor angle is obtained;

[0032] The estimated rotor angle and the compensated rotor angle are added to obtain the rotor angle.

[0033] Optionally, the speed of the ventilator turbine is controlled to a target speed based on the rotor angle and the FOC control method, including:

[0034] The turbine rotor angle is calculated and processed by means of space vector pulse width modulation to obtain the three-phase PWM duty cycle;

[0035] According to the three-phase PWM duty cycle, the speed of the ventilator turbine is controlled to the target speed through FOC control.

[0036] Optionally, the target treatment pressure required by the patient and the actual pressure of the ventilator turbine are obtained to obtain the target speed of the ventilator turbine, including:

[0037] Acquiring the actual pressure of the ventilator turbine based on a sensor in the ventilator;

[0038] According to the actual pressure and the target treatment pressure, the corresponding pressure error is obtained;

[0039] The pressure error is input to the second PI controller, and the output of the second PI controller is used as the target speed of the ventilator turbine.

[0040] On the other hand, an embodiment of the present application provides a speed control device for a ventilator turbine, the device comprising:

[0041] A data acquisition module, used for acquiring the actual component of the stator current and the phase voltage component of the ventilator turbine;

[0042] The rotor angle determination module is used to input the actual component of the stator current and the phase voltage component into the sliding mode observer to obtain the rotor angle of the ventilator turbine.

[0043] The speed control module is used to obtain the target treatment pressure required by the patient and the actual pressure of the ventilator turbine, and obtain the target speed of the ventilator turbine; based on the rotor angle and FOC control method, the speed of the ventilator turbine is controlled to the target speed.

[0044] Optionally, when the rotor angle determination module inputs the actual component of the stator current and the voltage information into the sliding mode observer to obtain the rotor angle of the ventilator turbine, it is specifically used to:

[0045] Obtaining an equation of a sliding mode observer, and inputting the actual component of the stator current and the phase voltage component into the equation of the sliding mode observer to obtain an estimated back electromotive force;

[0046] Based on the estimated back EMF, the rotor angle of the ventilator turbine is obtained.

[0047] Alternatively, the equations for the sliding mode observer are obtained as follows:

[0048] Obtain the voltage equation of the surface-mounted permanent magnet synchronous motor in the ventilator in a two-phase stationary coordinate system;

[0049] Based on the voltage equation, the equation of the sliding mode observer is established.

[0050] Alternatively, the equation for the sliding mode observer is as follows:

[0051]

[0052] in, and is the stator current estimation component, and is the difference between the estimated component of stator current and the actual component of stator current, u α and u β is the phase voltage component, L s is the stator inductance, and R is the stator resistance.

[0053] Optionally, when the rotor angle determination module inputs the actual component of the stator current and the phase voltage component into the equation of the sliding mode observer to obtain the estimated back electromotive force, it is specifically used to:

[0054] Based on the actual component of the stator current, the phase voltage component and the equation of the sliding mode observer, an error representation of the estimated value of the stator current is determined;

[0055] Obtaining sliding surface parameter values ​​and sliding surface representation expressions;

[0056] Based on defining sliding surface parameter values, defining a sliding surface representation expression, and an estimation value error representation expression, an estimated back electromotive force is obtained.

[0057] Optionally, the estimated back EMF is expressed as:

[0058]

[0059] in, and To estimate the back EMF, and is the difference between the estimated component of the stator current and the actual component of the stator current, and K is the adjustment parameter.

[0060] Optionally, when the rotor angle determination module obtains the rotor angle of the ventilator turbine based on the estimated back electromotive force, it is specifically used to:

[0061] Perform low-pass filtering on the estimated back electromotive force to obtain a target back electromotive force; obtain the angular velocity and the low-pass filter cutoff frequency of the surface-mounted permanent magnet synchronous motor, and process the target back electromotive force according to the angular velocity and the low-pass filter cutoff frequency to obtain a rotor angle; or,

[0062] The initial stator angle value is obtained, and the sine and cosine values ​​of the initial stator angle value are multiplied by the estimated back electromotive force to obtain a product value; the product value is input into the first PI controller for iterative processing until the error of the first PI regulator meets the requirements to obtain an estimated angular velocity; the estimated angular velocity is integrated to obtain the rotor angle.

[0063] Optionally, when the rotor angle determination module processes the target back electromotive force according to the angular velocity and the low-pass filter cutoff frequency to obtain the rotor angle, it is specifically used to:

[0064] Performing inverse tangent processing on the target back EMF to obtain the estimated rotor angle;

[0065] According to the angular velocity and the cutoff frequency of the low-pass filter, the compensated rotor angle is obtained;

[0066] The estimated rotor angle and the compensated rotor angle are added to obtain the rotor angle.

[0067] Optionally, the speed of the ventilator turbine is controlled to a target speed based on the rotor angle and the FOC control method, including:

[0068] The turbine rotor angle is calculated and processed by means of space vector pulse width modulation to obtain the three-phase PWM duty cycle;

[0069] According to the three-phase PWM duty cycle, the speed of the ventilator turbine is controlled to the target speed through FOC control.

[0070] Optionally, when the speed control module obtains the target treatment pressure required by the patient and the actual pressure of the ventilator turbine to obtain the target speed of the ventilator turbine, it is specifically used to:

[0071] Acquiring the actual pressure of the ventilator turbine based on a sensor in the ventilator;

[0072] According to the actual pressure and the target treatment pressure, the corresponding pressure error is obtained;

[0073] The pressure error is input to the second PI controller, and the output of the second PI controller is used as the target speed of the ventilator turbine.

[0074] On the other hand, an embodiment of the present application provides an electronic device, including a processor and a memory:

[0075] The memory is configured to store machine-readable instructions, which, when executed by the processor, cause the processor to perform any one of the methods for controlling the rotation speed of a ventilator turbine.

[0076] The beneficial effects brought by the technical solution provided in the embodiments of the present application include at least:

[0077] In an embodiment of the present application, the rotor angle is determined by the sliding mode observer in the ventilator, and then the control of the ventilator turbine can be achieved through the FOC control method based on the obtained rotor angle. That is, the present application uses a synovial observer to obtain the rotor angle of the turbine, which will have good robustness. And compared with other Hall-free drive methods, since the equation of the sliding mode observer has only one adjustment parameter, at this time, only the one adjustment parameter needs to be adjusted to make the turbine output a smoother flow and pressure, which is insensitive to the parameters of the turbine motor, improves the development efficiency, and also has high reliability, increasing the comfort and therapeutic effect of the ventilator.

[0078] In addition, in the embodiment of the present application, the speed of the ventilator turbine is finally controlled to the target speed based on the obtained rotor angle through the sliding mode observer and FOC control method. It can be seen that the present application does not rely on the traditional Hall signal when controlling the speed of the ventilator turbine, and uses magnetic field oriented control of the turbine, so that the turbine torque is smoother and the noise and vibration are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0080] Figure 1 A schematic flow chart of a method for controlling the rotation speed of a ventilator turbine provided in an embodiment of the present application;

[0081] Figure 2 A block diagram of the phase-locked loop principle provided in the embodiment of the present application;

[0082] Figure 3 A schematic diagram of magnetic field oriented control provided in an embodiment of the present application;

[0083] Figure 4 A schematic diagram of the structure of a speed control device for a ventilator turbine provided in an embodiment of the present application;

[0084] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0085] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be interpreted as limiting the present invention.

[0086] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be an intermediate element. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0087] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0088] Field-Oriented Control (FOC) is an advanced control method for motor drive, mainly used in brushless DC motors (BLDC) and AC motors (AC motor), especially asynchronous motors and permanent magnet synchronous motors (PMSM). Its main purpose is to improve the efficiency, dynamic performance and response speed of the motor.

[0089] Space Vector Pulse Width Modulation (SVPWM): is a PWM (Pulse Width Modulation) technology used to control motor drives, especially for three-phase inverter systems. The main purpose of SVPWM is to increase the utilization of the inverter output voltage and improve the performance of the motor, including its efficiency and drive quality.

[0090] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0091] Specifically, Figure 1 As shown, the method may include:

[0092] Step S101, obtaining the actual component of the stator current and the phase voltage component of the ventilator turbine.

[0093] Optionally, in order to ensure that the control of the ventilator matches the current ventilator, real-time parameters are required when controlling the ventilator turbine, such as the actual component of the stator current and the phase voltage component of the ventilator turbine, and the phase voltage component is a two-phase voltage component obtained by coordinate transformation based on the actual voltage information of the ventilator turbine.

[0094] Step S102, inputting the actual component of the stator current and the phase voltage component into the sliding mode observer to obtain the rotor angle of the ventilator turbine.

[0095] Optionally, after obtaining the actual stator current component and the phase voltage component of the ventilator turbine, the actual stator current component and the phase voltage component may be input into a sliding mode observer to obtain the rotor angle of the ventilator turbine.

[0096] In an optional embodiment of the present application, the actual component of the stator current and the voltage information are input into the sliding mode observer to obtain the rotor angle of the ventilator turbine, including:

[0097] Obtaining an equation of a sliding mode observer, and inputting the actual component of the stator current and the phase voltage component into the equation of the sliding mode observer to obtain an estimated back electromotive force;

[0098] Based on the estimated back EMF, the rotor angle of the ventilator turbine is obtained.

[0099] Optionally, the equation of the sliding mode observer determined in advance can be obtained, and the actual component of the stator current and the phase voltage component can be directly input into the equation of the sliding mode observer to obtain the estimated back electromotive force. Among them, the motor in the ventilator is a surface-mounted permanent magnet synchronous motor, and the back electromotive force representation of the surface-mounted permanent magnet synchronous motor is:

[0100]

[0101] Among them, ψ f is the permanent magnet flux, ω is the motor angular velocity, θ is the rotor angle, and R is the stator resistance.

[0102] At this time, it can be known based on the back electromotive force representation of the surface-mounted permanent magnet synchronous motor that the back electromotive force of the motor contains the position information of the motor (i.e., the rotor angle information). Therefore, after obtaining the estimated back electromotive force, the present application can obtain the rotor angle of the ventilator turbine based on the estimated back electromotive force. The equation of the sliding mode observer is determined in advance based on the working principle and properties of the motor in the ventilator, and can be directly obtained when applied.

[0103] In an optional embodiment of the present application, the equation of the sliding mode observer is obtained in the following manner:

[0104] Obtain the voltage equation of the surface-mounted permanent magnet synchronous motor in the ventilator in a two-phase stationary coordinate system;

[0105] According to the voltage equation, the equation of sliding mode observer is established;

[0106] The equation for the sliding mode observer is as follows:

[0107]

[0108] in, and is the estimated component of stator current, and is the difference between the estimated component of stator current and the actual component of stator current, u α and u β is the phase voltage component, L s is the stator inductance, R is the stator resistance;

[0109] Optionally, the motor in the ventilator can be a surface mounted permanent magnet synchronous motor. In this case, the equation of the sliding mode observer in the ventilator can be obtained based on the voltage equation of the surface mounted permanent magnet synchronous motor in a two-phase stationary coordinate system. Specifically, the voltage equation of the surface mounted permanent magnet synchronous motor in a two-phase stationary coordinate system can be obtained:

[0110]

[0111] Among them, u α and u β is the phase voltage component, i α and i β is the actual stator current component, L s is the stator inductance, e α and e β is the back electromotive force component, and R is the stator resistance.

[0112] Furthermore, it can be seen from the back-EMF representation corresponding to the surface-mounted permanent magnet synchronous motor that the back-EMF of the motor contains the position information of the motor, and estimating the back-EMF information is the main function of the sliding mode observer. At this time, the voltage equation of the surface-mounted permanent magnet synchronous motor in the two-phase stationary coordinate system can be sorted out based on the back-EMF representation to obtain:

[0113]

[0114] Furthermore, the equation of the sliding mode observer can be obtained based on the electromagnetic parameters corresponding to the surface-mounted permanent magnet synchronous motor, as shown below:

[0115]

[0116] in, and is the estimated component of the stator current (which can be determined based on the actual component of the stator current of the ventilator turbine), and is the difference between the estimated component of stator current and the actual component of stator current, u α and u β is the phase voltage component, L d is the stator inductance, and R is the stator resistance.

[0117] In an optional embodiment of the present application, the actual component of the stator current and the phase voltage component are input into the equation of the sliding mode observer to obtain an estimated back electromotive force, including:

[0118] Based on the actual component of the stator current, the phase voltage component and the equation of the sliding mode observer, an error representation of the estimated value of the stator current is determined;

[0119] Obtaining sliding surface parameter values ​​and sliding surface representation expressions;

[0120] Based on defining sliding surface parameter values, defining a sliding surface representation expression, and an estimation value error representation expression, an estimated back electromotive force is obtained.

[0121] Optionally, after determining the equation of the sliding mode observer, the error representation of the estimated value of the stator current can be determined according to the previously acquired actual component of the stator current, the phase voltage component and the determined equation of the sliding mode observer, specifically:

[0122]

[0123] in, and is the difference between the estimated component of stator current and the actual component of stator current, u α and u β is the phase voltage component, L s is the stator inductance, R is the stator resistance, e α and e β is the back electromotive force component, and K is the adjustment parameter.

[0124] Then, the sliding surface parameter value and the sliding surface expression can be obtained, and the estimated back electromotive force can be obtained based on the sliding surface parameter value and the sliding surface expression and the estimated value error expression. Among them, the sliding surface expression is:

[0125]

[0126] Furthermore, defining the sliding surface parameter value means setting At this point, it can be determined that the current output by the sliding mode observer is equal to the actual output, that is:

[0127]

[0128] Accordingly, when When , the estimated value error expression of the stator current is combined to obtain the estimated back electromotive force equation:

[0129]

[0130] in, and To estimate the back EMF, and is the difference between the estimated component of the stator current and the actual component of the stator current, and K is the adjustment parameter.

[0131] In an optional embodiment of the present application, the rotor angle of the ventilator turbine is obtained based on the estimated back electromotive force, including:

[0132] Perform low-pass filtering on the estimated back electromotive force to obtain a target back electromotive force; obtain the angular velocity and the low-pass filter cutoff frequency of the surface-mounted permanent magnet synchronous motor, and process the target back electromotive force according to the angular velocity and the low-pass filter cutoff frequency to obtain a rotor angle; or,

[0133] The initial stator angle value is obtained, and the sine and cosine values ​​of the initial stator angle value are multiplied by the estimated back electromotive force to obtain a product value; the product value is input into a first PI (Proportional-Integral) controller for iterative processing until the error of the PI regulator meets the requirements to obtain an estimated angular velocity; the estimated angular velocity is integrated to obtain the rotor angle.

[0134] Optionally, in practical applications, the rotor angle of the ventilator turbine can be determined based on two methods, namely, a method of calculating the rotor angle by an inverse tangent and a method of calculating the rotor angle by a phase-locked loop. The two methods are described in detail below.

[0135] 1. Calculate the rotor angle by inverse tangent:

[0136] Optionally, after obtaining the estimated back electromotive force, the estimated back electromotive force can be low-pass filtered to obtain the target back electromotive force, the angular velocity and low-pass filter cutoff frequency of the surface-mounted permanent magnet synchronous motor can be obtained, and the target back electromotive force can be further processed according to the angular velocity and the low-pass filter cutoff frequency to obtain the rotor angle.

[0137] In an optional embodiment of the present application, the target back electromotive force is processed according to the angular velocity and the low-pass filter cutoff frequency to obtain the rotor angle, including:

[0138] Performing inverse tangent processing on the target back EMF to obtain the estimated rotor angle;

[0139] According to the angular velocity and the cutoff frequency of the low-pass filter, the compensated rotor angle is obtained;

[0140] The estimated rotor angle and the compensated rotor angle are added to obtain the rotor angle.

[0141] Optionally, the target back EMF can be processed by inverse tangent to obtain the estimated rotor angle, that is:

[0142]

[0143] in, To estimate the rotor angle, and is the target back EMF.

[0144] Furthermore, since the target back EMF has passed through a low-pass filter, the angle calculated at this time needs to compensate for the phase caused by the filter, so it is necessary to obtain the compensated rotor angle based on the angular velocity and the low-pass filter cutoff frequency. Specifically, the estimated angular velocity of the motor can be obtained based on the estimated rotor angle. Right now:

[0145]

[0146] Then, the phase delay caused by the low-pass filter is compensated based on the motor angular velocity to obtain the compensated rotor angle:

[0147]

[0148] in, Estimate the angular velocity for the motor, ω c *f s is the cut-off frequency of the low-pass filter, and θ1 is the compensation rotor angle.

[0149] Finally, the starting rotor angle and the compensation rotor angle can be added to obtain the rotor angle finally output by the sliding mode observer, that is:

[0150]

[0151] Where θ is the rotor angle, θ1 is the compensation rotor angle, To estimate the rotor angle.

[0152] 2. How the phase-locked loop calculates the angle:

[0153] The initial stator angle value is obtained, and the initial stator angle value is multiplied by the estimated back electromotive force to obtain the product value; the product value is input into the first PI controller for iterative processing until the error of the first PI regulator meets the requirements, and the estimated angular velocity is obtained; the estimated angular velocity is integrated to obtain the rotor angle

[0154] Optionally, when calculating the rotor angle based on the phase-locked loop, the estimated back electromotive force (or flux linkage signal) is multiplied by the sine and cosine results of the acquired initial stator angle value to obtain a product value, and then the product value is input into the first PI controller for iterative processing until the error of the first PI regulator meets the requirements (such as when the error tends to zero), at which time the first PI regulator is the estimated angular speed of the motor. The formula principle of the first PI controller for iterative processing is as follows:

[0155]

[0156] in, and To estimate the back EMF, Δθ eis the difference between the rotor angles during two iterations, To estimate the angular speed, To estimate the rotor angle.

[0157] Furthermore, during the first PI regulator iteration, when Δθ e When the error of the first PI regulator is very small, then it is Δθ e , and the output of the first PI regulator is the estimated angular velocity At this time, the estimated angular velocity can be Then integrate to get the rotor angle.

[0158] Optional, such as Figure 2 As shown, the present application provides a phase-locked loop principle block diagram, and the following is combined with Figure 2 The way the phase-locked loop calculates the angle is explained again.

[0159] Specifically, estimate the back EMF and (In the figure, it is represented by Eα and Eβ, i.e., the back electromotive force of the motor in the two-phase stationary coordinate system) is input as the input signal to the motor control system. The signal output from Eα and Eβ passes through the negative feedback link and is compared with other signals, i.e., Eα and Eβ are processed accordingly using cosine and sine functions to generate a signal related to the motor rotor angle. Further, the error Δe is calculated by comparing the input signal and the feedback signal. The PI controller converts the error Δe into a control signal. The PI controller consists of two parts: proportional (P) and integral (I). The rotor angle of the motor is then calculated by the integral method. and estimated angular velocity The motor movement is monitored and fed back to the control system. The control system optimizes the motor's operating performance through precise feedback and real-time control, and makes each part work together to ensure that the motor is adjusted according to the set speed and position.

[0160] Step S103, obtaining the target treatment pressure required by the patient and the actual pressure of the ventilator turbine, and obtaining the target rotation speed of the ventilator turbine.

[0161] Optionally, because the patient needs to be treated based on a ventilator, the oxygen concentration ultimately output by the ventilator needs to match the patient's condition. Therefore, in this application, the target treatment pressure required by the patient (i.e., the pressure ultimately required by the patient) and the actual pressure of the ventilator turbine are also obtained through sensors. Then, the target speed of the ventilator turbine is obtained based on the target treatment pressure and the actual pressure of the ventilator turbine.

[0162] In an optional embodiment of the present application, the target treatment pressure required by the patient and the actual pressure of the ventilator turbine are obtained to obtain the target rotation speed of the ventilator turbine, including:

[0163] Acquiring the actual pressure of the ventilator turbine based on a sensor in the ventilator;

[0164] According to the actual pressure and the target treatment pressure, the corresponding pressure error is obtained;

[0165] The pressure error is input to the second PI controller, and the output of the second PI controller is used as the target speed of the ventilator turbine.

[0166] Optionally, in order to ensure that the final target speed matches the target pressure required by the patient, the patient's current actual pressure can be obtained based on the sensor in the ventilator, and then the pressure error between the actual pressure and the target treatment pressure can be determined. Finally, the pressure error is input into the second PI controller, and the output of the second PI controller is used as the target speed of the ventilator turbine.

[0167] Step S104, controlling the rotation speed of the ventilator turbine to a target rotation speed based on the rotor angle and the FOC control method.

[0168] Optionally, after obtaining the rotor angle, the speed of the ventilator turbine can be controlled based on the rotor angle and the FOC control method. In an optional embodiment of the present application, the speed of the ventilator turbine is controlled to a target speed based on the rotor angle and the FOC control method, including:

[0169] The turbine rotor angle is calculated and processed by means of space vector pulse width modulation to obtain the three-phase PWM duty cycle;

[0170] According to the three-phase PWM duty cycle, the speed of the ventilator turbine is controlled to the target speed through FOC control.

[0171] Optionally, after the rotor angle is determined, the turbine rotor angle can be calculated and processed by space vector pulse width modulation to obtain a three-phase PWM duty cycle, and then the speed of the ventilator turbine can be controlled to a target speed by FOC control based on the obtained three-phase PWM duty cycle.

[0172] When determining the three-phase PWM duty cycle of the ventilator turbine based on the obtained rotor angle, the reference voltage corresponding to the ventilator turbine (i.e., u d and u q ), and then transform the reference voltage into u in the two-phase coordinate system through coordinate transformation. α and u βFurthermore, the target sector and the corresponding basic vector action corresponding to the two-phase voltage are determined based on the SVPWM modulation mode, and then the basic vector action time corresponding to the target sector is determined based on the determined two-phase voltage, and the basic vector action time corresponding to the target sector is further calculated and processed to obtain the duty cycle of the three-phase PWM value in the FOC control mode.

[0173] Optional, such as Figure 3 As shown, the present application embodiment provides a magnetic field oriented control principle diagram. Figure 3 The method of controlling the speed of the ventilator turbine to the target speed by using the sliding mode observer and FOC control method is described. Specifically:

[0174] First, the target speed (i.e., Reference Speed) is used as the input signal, and then the control command is generated through the signal adder (Σ in the figure). Then, the built-in PI controller processes different current reference signals separately, specifically by comparing the reference signal (i q-ref ) and the actual measured signal (i a ), calculate the error (difference) and generate the corresponding control output. The three-phase signals (such as a, b, c) are further converted into direct current (d and q components) and orthogonal components (α and β) for easy control and analysis. The position and speed estimator estimates the real-time position and speed of the motor by analyzing the current and voltage signals, and feeds the results back to the control system. The three-phase bridge controls the power of the motor through the space vector pulse width modulation (SVPWM) technology to achieve efficient drive. It can be seen that the method based on the embodiment of the present application can achieve precise control of the motor to stabilize its operating performance, so that it can automatically adjust the corresponding voltage and current according to the set reference speed, thereby achieving precise control of the ventilator turbine.

[0175] In the embodiment of the present application, the control of the turbine speed of the ventilator does not rely on the Hall signal, and the magnetic field oriented control is adopted, so that the turbine torque is smoother, noise and vibration can be reduced, and compared with other non-Hall drive methods, the synovial observer adopted in the present application obtains the angle of the turbine rotor, which has good robustness, and only needs to adjust one adjustment parameter to make the turbine output more stable flow and pressure, which is insensitive to the parameters of the turbine motor, and improves the development efficiency. At the same time, it has high reliability and increases the comfort and therapeutic effect of the ventilator.

[0176] The present application embodiment provides a speed control device for a ventilator turbine, such as Figure 4 As shown, the device may include: a data acquisition module 401, a rotor angle determination module 402 and a speed control module 403, wherein:

[0177] A data acquisition module, used for acquiring the actual component of the stator current and the phase voltage component of the ventilator turbine;

[0178] The rotor angle determination module is used to input the actual component of the stator current and the phase voltage component into the sliding mode observer to obtain the rotor angle of the ventilator turbine.

[0179] The speed control module is used to obtain the target treatment pressure required by the patient and the actual pressure of the ventilator turbine, and obtain the target speed of the ventilator turbine; based on the rotor angle and FOC control method, the speed of the ventilator turbine is controlled to the target speed.

[0180] Optionally, when the rotor angle determination module inputs the actual component of the stator current and the voltage information into the sliding mode observer to obtain the rotor angle of the ventilator turbine, it is specifically used to:

[0181] Obtaining an equation of a sliding mode observer, and inputting the actual component of the stator current and the phase voltage component into the equation of the sliding mode observer to obtain an estimated back electromotive force;

[0182] Based on the estimated back EMF, the rotor angle of the ventilator turbine is obtained.

[0183] Alternatively, the equations for the sliding mode observer are obtained as follows:

[0184] Obtain the voltage equation of the surface-mounted permanent magnet synchronous motor in the ventilator in a two-phase stationary coordinate system;

[0185] According to the voltage equation, the equation of sliding mode observer is established;

[0186] The equation for the sliding mode observer is as follows:

[0187]

[0188] in, and is the stator current estimation component, and is the difference between the estimated component of stator current and the actual component of stator current, u α and u β is the phase voltage component, L s is the stator inductance, and R is the stator resistance.

[0189] Optionally, when the rotor angle determination module inputs the actual component of the stator current and the phase voltage component into the equation of the sliding mode observer to obtain the estimated back electromotive force, it is specifically used to:

[0190] Based on the actual component of the stator current, the phase voltage component and the equation of the sliding mode observer, an error representation of the estimated value of the stator current is determined;

[0191] Obtaining sliding surface parameter values ​​and sliding surface representation expressions;

[0192] Based on defining sliding surface parameter values, defining a sliding surface representation expression, and an estimation value error representation expression, an estimated back electromotive force is obtained.

[0193] Optionally, the estimated back EMF is expressed as:

[0194]

[0195] in, and To estimate the back EMF, and is the difference between the estimated component of the stator current and the actual component of the stator current, and K is the adjustment parameter.

[0196] Optionally, when the rotor angle determination module obtains the rotor angle of the ventilator turbine based on the estimated back electromotive force, it is specifically used to:

[0197] Perform low-pass filtering on the estimated back electromotive force to obtain a target back electromotive force; obtain the angular velocity and the low-pass filter cutoff frequency of the surface-mounted permanent magnet synchronous motor, and process the target back electromotive force according to the angular velocity and the low-pass filter cutoff frequency to obtain a rotor angle; or,

[0198] The initial stator angle value is obtained, and the sine and cosine values ​​of the initial stator angle value are multiplied by the estimated back electromotive force to obtain a product value; the product value is input into the first PI controller for iterative processing until the error of the first PI regulator meets the requirements to obtain an estimated angular velocity; the estimated angular velocity is integrated to obtain the rotor angle.

[0199] Optionally, when the rotor angle determination module processes the target back electromotive force according to the angular velocity and the low-pass filter cutoff frequency to obtain the rotor angle, it is specifically used to:

[0200] Performing inverse tangent processing on the target back EMF to obtain the estimated rotor angle;

[0201] According to the angular velocity and the cutoff frequency of the low-pass filter, the compensated rotor angle is obtained;

[0202] The estimated rotor angle and the compensated rotor angle are added to obtain the rotor angle.

[0203] Optionally, the speed of the ventilator turbine is controlled to a target speed based on the rotor angle and the FOC control method, including:

[0204] The turbine rotor angle is calculated and processed by means of space vector pulse width modulation to obtain the three-phase PWM duty cycle;

[0205] According to the three-phase PWM duty cycle, the speed of the ventilator turbine is controlled to the target speed through FOC control.

[0206] Optionally, when the speed control module obtains the target treatment pressure required by the patient and the actual pressure of the ventilator turbine to obtain the target speed of the ventilator turbine, it is specifically used to:

[0207] Acquiring the actual pressure of the ventilator turbine based on a sensor in the ventilator;

[0208] According to the actual pressure and the target treatment pressure, the corresponding pressure error is obtained;

[0209] The pressure error is input to the second PI controller, and the output of the second PI controller is used as the target speed of the ventilator turbine.

[0210] A speed control device for a ventilator turbine in this embodiment can execute a speed control method for a ventilator turbine shown in an embodiment of the present application. The implementation principle is similar and will not be repeated here.

[0211] An embodiment of the present application provides an electronic device, and the electronic device in the embodiment of the present application includes: a processor; and a memory, the memory is configured to store machine-readable instructions, and when the instructions are executed by the processor, the processor executes a method for controlling the speed of a ventilator turbine.

[0212] Compared with the prior art, the invention can realize: when controlling the turbine speed of the ventilator, it does not rely on the Hall signal, but adopts magnetic field oriented control, so that the turbine torque is smoother, noise and vibration can be reduced, and compared with other non-Hall drive methods, the synovial observer adopted in this application obtains the angle of the turbine rotor, which has good robustness, and the synovial observer only includes one adjustment parameter, which is insensitive to the parameters of the turbine motor. At this time, only one adjustment parameter needs to be adjusted to make the turbine output a smoother flow and pressure, thereby improving development efficiency. At the same time, it has high reliability, which increases the comfort and therapeutic effect of the ventilator.

[0213] The present application embodiment provides an electronic device, such as Figure 5 As shown, Figure 5 The electronic device shown includes: a processor 2001 and a memory 2003. The processor 2001 and the memory 2003 are connected, such as through a bus 2002. Optionally, the electronic device 2000 may also include a transceiver 2004. It should be noted that in actual applications, the transceiver 2004 is not limited to one, and the structure of the electronic device 2000 does not constitute a limitation on the embodiments of the present application.

[0214] Processor 2001 may be a CPU, a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, a transistor logic device, a hardware component or any combination thereof. It may implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of this application. Processor 2001 may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0215] The bus 2002 may include a path to transmit information between the above components. The bus 2002 may be a PCI bus or an EISA bus, etc. The bus 2002 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0216] The memory 2003 may be a ROM or other type of static storage device that can store static information and instructions, a RAM or other type of dynamic storage device that can store information and instructions, or an EEPROM, a CD-ROM or other optical disk storage, an optical disk storage (including a compressed optical disk, a laser disk, an optical disk, a digital versatile disk, a Blu-ray disk, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited to these.

[0217] The memory 2003 is used to store the application code for executing the solution of the present application, and the execution is controlled by the processor 2001. The processor 2001 is used to execute the application code stored in the memory 2003 to implement Figure 4 The illustrated embodiment provides an operation of a speed control device for a ventilator turbine.

[0218] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0219] The above is only part of the embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for controlling the rotation speed of a ventilator turbine, characterized in that: include: Obtaining actual components of stator current and phase voltage components of the ventilator turbine; Inputting the actual component of the stator current and the phase voltage component into a sliding mode observer to obtain a rotor angle of the ventilator turbine; Obtaining the target treatment pressure required by the patient and the actual pressure of the ventilator turbine, and obtaining the target rotation speed of the ventilator turbine; The rotation speed of the ventilator turbine is controlled to the target rotation speed based on the rotor angle and the FOC control method.

2. The method according to claim 1, characterized in that The step of inputting the actual component of the stator current and the voltage information into a sliding mode observer to obtain a rotor angle of a ventilator turbine comprises: Obtaining an equation of the sliding mode observer, and inputting the actual component of the stator current and the phase voltage component into the equation of the sliding mode observer to obtain an estimated back electromotive force; Based on the estimated back electromotive force, the rotor angle of the ventilator turbine is obtained.

3. The method according to claim 2, characterized in that The equation of the sliding mode observer is obtained in the following way: Obtain the voltage equation of the surface-mounted permanent magnet synchronous motor in the ventilator in a two-phase stationary coordinate system; According to the voltage equation, establishing the equation of the sliding mode observer; The equation of the sliding mode observer is as follows: in, and is the stator current estimation component, and is the difference between the estimated component of stator current and the actual component of stator current, u α and u β is the phase voltage component, L s is the stator inductance, and R is the stator resistance.

4. The method according to claim 2, characterized in that: The actual component of the stator current and the phase voltage component are input into the equation of the sliding mode observer to obtain the estimated back electromotive force, including: Determining an error representation of an estimated value of the stator current based on the actual component of the stator current, the phase voltage component, and an equation of the sliding mode observer; Obtaining sliding surface parameter values ​​and sliding surface representation expressions; The estimated back electromotive force is obtained based on the defined sliding surface parameter value, the defined sliding surface representation and the estimated value error representation.

5. The method according to claim 4, characterized in that The estimated back EMF is expressed as follows: in, and To estimate the back EMF, and is the difference between the estimated component of the stator current and the actual component of the stator current, and K is the adjustment parameter.

6. The method according to claim 3, characterized in that The step of obtaining the rotor angle of the ventilator turbine based on the estimated back electromotive force comprises: performing low-pass filtering on the estimated back electromotive force to obtain a target back electromotive force; obtaining the angular velocity and the low-pass filter cutoff frequency of the surface-mounted permanent magnet synchronous motor, and processing the target back electromotive force according to the angular velocity and the low-pass filter cutoff frequency to obtain the rotor angle; or, An initial stator angle value is obtained, and the sine and cosine values ​​of the initial stator angle value are multiplied by the estimated back electromotive force to obtain a product value; the product value is input into a first PI controller for iterative processing until the error of the first PI regulator meets the requirements to obtain an estimated angular velocity; the estimated angular velocity is integrated to obtain the rotor angle.

7. The method according to claim 6, characterized in that The step of processing the target back electromotive force according to the angular velocity and the low-pass filter cutoff frequency to obtain the rotor angle includes: Performing inverse tangent processing on the target back electromotive force to obtain an estimated rotor angle; Obtaining a compensated rotor angle according to the angular velocity and the low-pass filter cutoff frequency; The estimated rotor angle and the compensated rotor angle are added to obtain the rotor angle.

8. The method according to claim 1, characterized in that The step of controlling the rotation speed of the ventilator turbine to the target rotation speed based on the rotor angle and the FOC control method includes: The turbine rotor angle is calculated and processed by means of space vector pulse width modulation to obtain the three-phase PWM duty cycle; According to the three-phase PWM duty cycle, the rotation speed of the ventilator turbine is controlled to the target rotation speed through the FOC control method.

9. The method according to claim 1, characterized in that: The step of obtaining the target treatment pressure required by the patient and the actual pressure of the ventilator turbine to obtain the target rotation speed of the ventilator turbine includes: Acquiring the actual pressure of the ventilator turbine based on a sensor in the ventilator; Obtaining a corresponding pressure error according to the actual pressure and the target treatment pressure; The pressure error is input to a second PI controller, and the output of the second PI controller is used as the target rotation speed of the ventilator turbine.

10. A speed control device for a ventilator turbine, characterized in that: include: A data acquisition module, used for acquiring the actual component of the stator current and the phase voltage component of the ventilator turbine; The rotor angle determination module is used to input the actual component of the stator current and the phase voltage component into the sliding mode observer to obtain the rotor angle of the ventilator turbine. The speed control module is used to obtain the target treatment pressure required by the patient and the actual pressure of the ventilator turbine, and obtain the target speed of the ventilator turbine; based on the rotor angle and FOC control method, the speed of the ventilator turbine is controlled to the target speed.

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