Flow-equalizing heat balance method for driving motor of deep-sea robot

Abstract

The invention discloses a deep-sea robot driving motor current-sharing heat balance method, which comprises the following steps of S1, constructing a differential equation set for describing input and output characteristics of a motor, and covering mechanical and electrical parts; s2, measuring the current and the rotating speed of each armature in real time, and calculating a current difference value; s3, constructing a parameter matrix and a solution matrix for calculating a control gain, and establishing a weight matrix and an adjustment coefficient for dynamically calculating a control signal; s4, updating the control weight matrix in real time according to the current difference value, iteratively updating the solution matrix, calculating a control voltage signal and applying the control voltage signal to each armature; the current-sharing heat balance method is based on the current signals of the armatures of the motor, the deviation signals are calculated, the control voltage is dynamically adjusted, it is ensured that the rotating speed of the motor accurately tracks the target signals, it is also ensured that currents of the armatures tend to be the same, heat balance between the armatures is achieved, and stable operation of the motor is ensured.

Description

Technical Field

[0001] The present invention relates to the field of deep-sea motor control technology, and more specifically, to a method for heat balance of a deep-sea robot driving motor. Background Art

[0002] As a key marine operation tool, deep-sea robots are widely used in deep-sea exploration, resource development, and environmental monitoring. Deep-sea motors, as core power units, directly determine the overall performance of deep-sea robots. As deep-sea motors need to run for a long time and at high intensity, they easily generate a lot of heat. If the heat cannot be conducted and dissipated in a timely and effective manner, it will cause the motor to overheat, thereby reducing efficiency and even damaging the motor. The deep-sea environment has characteristics such as high water pressure, strong corrosiveness, and lack of natural convection, making it difficult for many traditional thermal management methods to be directly applied. Specific solutions need to be designed for these extreme conditions.

[0003] In order to optimize the heat dissipation efficiency of deep-sea motors, the motor structure layout, key component materials, oil circuit design and impeller can be optimized. Among them, the motor structure layout with multiple modular stators is an effective solution. This design divides the motor into multiple independent working areas, each partition is equipped with an independent stator, armature and impeller, and multiple armatures are used to drive the shaft in coordination. Through this multi-modular stator layout, the motor is divided into multiple thermal management areas, and heat can be more efficiently conducted and dispersed in each area. In the design of motors with multiple modular stators, by ensuring that the current of each armature converges under the overall load, the armature can be heated evenly and the thermal balance of the motor can be ensured. The core principle is to precisely control the driving voltage of the armature of each motor segment so that the current and heat generation of each armature are consistent, thereby avoiding uneven heating caused by local overload and ensuring that the motor maintains a stable temperature distribution while operating efficiently. Although the design of deep-sea robot drive motors with multiple modular stators has been proposed, the corresponding current-balanced thermal balance research and application are still in the exploratory stage. In particular, there is still a lack of systematic technical solutions on how to coordinate the current of each partition armature so that the motor maintains a consistent heat distribution under the overall load.

[0004] Therefore, it is necessary to propose a current-equalizing thermal balance method suitable for deep-sea robot drive motors with multiple modular stators to ensure that the motor can maintain a uniform and stable temperature distribution under different working conditions, thereby improving the working efficiency and reliability of the deep-sea robot motor system. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for heat balance of a deep-sea robot driving motor.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A method for heat balancing a deep-sea robot driving motor by balancing current, comprising the following steps:

[0008] Step S1, considering a DC motor with n modular stators, constructing a set of differential equations describing the input and output characteristics of the motor, covering both the mechanical part and the electrical part, for comprehensively describing the dynamic behavior of the motor;

[0009] Step S2, measuring the current value of each armature and the motor speed in real time, and calculating the standard deviation of the current and the current difference between each armature;

[0010] Step S3, constructing a parameter matrix required for calculating the control gain and a solution matrix for calculating the control signal, and constructing a control weight matrix and a weight adjustment coefficient for dynamically calculating the control signal;

[0011] Step S4, based on the calculated standard deviation and current difference, the control weight matrix is ​​updated in real time at a certain period, the solution matrix is ​​updated iteratively, the control voltage signal is calculated and applied to each armature.

[0012] Furthermore, the step S1 includes the following steps:

[0013] Step S101, construct variables and parameters describing the dynamic characteristics of the motor, variables Indicates motor output, variable represents the induced current of the jth armature, and the variable It represents the control voltage signal of the jth armature input, and the parameter is the resistance of the jth armature, parameter is the inductance of the jth armature, parameter is the viscous friction coefficient of the motor, and the parameter is the armature constant of the jth armature, is the electromotive force constant of the jth armature, for the jth armature, j=1,2,…,n;

[0014] Step S102, construct the mechanical part of the motor equation, according to the motor inertia load J multiplied by the derivative of the angular velocity equal to the sum of all torques of the motor shaft, to obtain the following equation:

[0015] (1)

[0016] In formula (1), It is a derivative operator, which means the derivative of a variable with respect to time t;

[0017] Step S103, constructing the electrical part of the motor equation, and obtaining the following equation according to the relationship between the applied voltage, induced electromotive force, resistance voltage and inductance voltage of each armature:

[0018] (2)

[0019] In formula (2), is the induced electromotive force of the jth armature;

[0020] Step S104, construct a differential equation group describing the motor behavior. Based on equation (1) and equation (2), the differential equation describing the motor behavior can be obtained:

[0021] (3)

[0022] In formula (3), the first row of equations is used to describe the applied voltage With the induction current The relationship between the second row of equations is used to describe the induced current The angular velocity of the motor shaft The relationship between.

[0023] Furthermore, step S2 includes the following steps:

[0024] Step S201, real-time measurement of the current value of each armature in the motor , ( j = 1, 2, ..., n) and motor speed ;

[0025] Step S202, calculate the average current of each armature ;

[0026] Step S203, calculating the standard deviation of the current of each armature ,symbol Indicates absolute value;

[0027] Step S204, calculating the difference between the armature currents , k = 1, 2, …, n, .

[0028] Furthermore, step S3 includes the following steps:

[0029] Step S301: construct the parameter matrix required for calculating the control gain , and ,

[0030] , , ,

[0031] , , , ,

[0032] , , where diag(V) means generating a diagonal matrix with vector V as the diagonal element. Represents the transpose operation of a matrix or vector;

[0033] Step S302, construct an iterative solution matrix for calculating the control signal, construct Dimensional real iterative solution matrix And assign initial values ​​to make it positive definite or semi-positive definite;

[0034] Step S303: construct a control weight matrix , build dimensional real positive definite matrix And assign initial value ,in, represent dimensional identity matrix;

[0035] Step S304: construct weight adjustment coefficient , construct positive real numbers And assign a value.

[0036] Furthermore, the step S4 includes the following steps:

[0037] Step S401, calculate the current deviation matrix according to a certain period ,

[0038] (4)

[0039] Step S402: Update the control weight matrix at a certain period. The value of is updated to ;

[0040] Step S403, when the control weight matrix When the value of is updated, iterative calculation is performed and the iterative solution matrix is ​​updated according to formula (5) The numerical value of

[0041] (5)

[0042] In formula (5), Represents the solution matrix The value after completing the kth iteration;

[0043] Step S404, after each iteration, calculate and The difference between the two, check the convergence conditions

[0044] (6)

[0045] If the convergence condition in equation (6) is not met, then return to step S403 and continue iterating. If the convergence condition is met, then stop iterating and output , in formula (6), is a preset small positive number to determine whether the solution converges. represents the matrix norm;

[0046] Step S405, calculate the control signal according to formula (7)

[0047] (7)

[0048] in, , , is the set motor speed target signal;

[0049] Step S406: The voltage signal calculated in equation (7) is Drive each armature and return to step S401.

[0050] The beneficial effects of the present invention are:

[0051] The present invention monitors the current signals of each armature in the deep-sea robot drive motor in real time, calculates its deviation signal and dynamically updates the control voltage signal, which not only ensures that the motor speed accurately tracks the target signal, but also ensures that when there are deviations in the armature parameters, the armature currents tend to be consistent, thereby achieving thermal balance between the armatures and ensuring stable operation of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A schematic diagram of a control structure of the current-sharing heat balance method for the deep-sea robot driving motor in this embodiment;

[0053] Figure 2 A flow chart of the heat balance method for the deep-sea robot driving motor in this embodiment;

[0054] Figure 3 This is an effect diagram of the method for equalizing the flow and balancing the heat of the deep-sea robot driving motor in this embodiment. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] Embodiment: A method for balancing the current of a deep-sea robot driving motor is based on real-time detection of the armature current of each partition and calculation of its mean and deviation, and then dynamically adjusting the control weight matrix and updating the control voltage accordingly, so that the armature current converges, thereby achieving balancing the current of each armature. Figure 1 The process of implementing thermal balance control in the embodiment is as follows: for the deep-sea robot drive motor with multiple modular stators, first complete the sensor configuration, independently configure a high-precision current sensor for each partition to collect the phase current signal in real time, use an encoder to accurately measure the motor speed signal, and all sensor data are synchronously transmitted to a high-performance workstation; then, the workstation realizes the real-time calculation of the control voltage signal. The workstation calculates each current difference in real time based on the current sensor data, and calculates the control voltage signal according to the steps S1-S4 in combination with the dynamically updated weight matrix and the speed tracking target; finally, the workstation applies the calculated control voltage signal to the motor through the motor driver; Figure 1 , Figure 2 As shown, the real-time calculation of the control voltage signal specifically includes the following steps:

[0057] Step S1, considering a DC motor with n modular stators, constructing a set of differential equations describing the input and output characteristics of the motor, covering both the mechanical part and the electrical part, for comprehensively describing the dynamic behavior of the motor;

[0058] Specifically, step S1 includes the following steps:

[0059] Step S101, construct variables and parameters describing the dynamic characteristics of the motor, variables Represents the motor output, that is, the angular velocity of the shaft, and the variable represents the induced current of the jth armature, and the variable It represents the control voltage signal (input control signal) input to the jth armature, and the parameter is the resistance of the jth armature, parameter is the inductance of the jth armature, parameter is the viscous friction coefficient of the motor, which represents the friction force on the shaft and the angular velocity of the shaft The proportional relationship between the parameters is the armature constant of the jth armature, which represents the torque and the current induced by the applied voltage The proportional relationship between is the electromotive force constant of the jth armature, which indicates the relationship between its induced electromotive force and the angular velocity of the shaft The proportional relationship is that for the jth armature, j=1,2,…,n;

[0060] Step S102, construct the mechanical part of the motor equation, according to the motor inertia load J multiplied by the derivative of the angular velocity equal to the sum of all torques of the motor shaft, to obtain the following equation:

[0061] (1)

[0062] In formula (1), It is a derivative operator, which means the derivative of a variable with respect to time t;

[0063] Step S103, constructing the electrical part of the motor equation, and obtaining the following equation according to the relationship between the applied voltage, induced electromotive force, resistance voltage and inductance voltage of each armature:

[0064] (2)

[0065] In formula (2), is the induced electromotive force of the jth armature;

[0066] Step S104, construct a differential equation group describing the motor behavior. Based on equation (1) and equation (2), the differential equation describing the motor behavior can be obtained:

[0067] (3)

[0068] In formula (3), the first row of equations is used to describe the applied voltage With the induction current The relationship between the second row of equations is used to describe the induced current The angular velocity of the motor shaft The relationship between.

[0069] Step S2, measuring the current value of each armature and the motor speed in real time, and calculating the standard deviation of the current and the current difference between each armature;

[0070] Specifically, step S2 includes the following steps:

[0071] Step S201, real-time measurement of the current value of each armature in the motor , ( j = 1, 2, ..., n) and motor speed ;

[0072] Step S202, calculate the average current of each armature ;

[0073] Step S203, calculating the standard deviation of the current of each armature ,symbol Indicates absolute value;

[0074] Step S204, calculating the difference between the armature currents , k = 1, 2, …, n, .

[0075] Step S3, constructing a parameter matrix required for calculating the control gain and a solution matrix for calculating the control signal, and constructing a control weight matrix and a weight adjustment coefficient for dynamically calculating the control signal;

[0076] Specifically, step S301 constructs a parameter matrix required for calculating the control gain , and ,

[0077] , , ,

[0078] , , , ,

[0079] , , where diag(V) means generating a diagonal matrix with vector V as the diagonal element. Represents the transpose operation of a matrix or vector;

[0080] Step S302, construct an iterative solution matrix for calculating the control signal, construct Dimensional real iterative solution matrix And assign an initial value to make it positive definite or semi-positive definite (for example, assign an initial value is a zero matrix or an identity matrix);

[0081] Step S303: construct a control weight matrix , build dimensional real positive definite matrix And assign initial value (For example ),in, represent dimensional identity matrix;

[0082] Step S304: construct weight adjustment coefficient , construct positive real numbers and assign values ​​(e.g. ), where increasing the adjustment weight coefficient The value can speed up the convergence of the armature currents, but too high a weight coefficient may cause oscillation in the motor output. On the contrary, reducing the weight coefficient can slow down the convergence speed and improve the stability of the system.

[0083] Step S4, according to the calculated standard deviation and current difference, the control weight matrix is ​​updated in real time at a certain period, the solution matrix is ​​updated iteratively, the control voltage signal is calculated and applied to each armature;

[0084] Specifically, step S4 includes the following steps:

[0085] Step S401, calculate the current deviation matrix at a certain period (e.g. 0.1s) ,

[0086] (4)

[0087] In formula (4), the matrix The diagonal elements of are the standard deviations obtained in step S203 The order of the matrix The off-diagonal elements in the jth row and kth column are the current difference values ​​obtained in step S204. ;

[0088] Step S402: Update the control weight matrix at a certain period (e.g. 0.1s). The value of The value of ;

[0089] Step S403, when the control weight matrix When the value of is updated, iterative calculation is performed and the iterative solution matrix is ​​updated according to formula (5) The numerical value of

[0090] (5)

[0091] In formula (5), Represents the solution matrix The value after completing the kth iteration;

[0092] Step S404, after each iteration, calculate and The difference between the two, check the convergence conditions

[0093] (6)

[0094] If the convergence condition in equation (6) is not met, then return to step S403 and continue iterating. If the convergence condition is met, then stop iterating and output , in formula (6), is a small positive number (e.g. ), to determine whether the solution converges, symbol represents the matrix norm;

[0095] Step S405, calculate the control signal according to formula (7)

[0096] (7)

[0097] in, , , is the set motor speed target signal;

[0098] Step S406: The voltage signal calculated in equation (7) is Drive each armature and return to step S401.

[0099] In this embodiment, the implementation structure of the current-equalizing heat balance method of the deep-sea robot drive motor with multiple modular stators is as follows: Figure 1 As shown, the current of each armature is collected in real time through the current sensor, and the speed of the motor shaft is obtained through the encoder. These current and speed signals are sent to the high-performance workstation. As the center of data processing and control, the high-performance workstation calculates the control signal according to the method in steps S1-S4 and sends it to the driver. The driver applies voltage according to the signal to control the operation of the motor.

[0100] In this embodiment, the deep-sea robot driving motor with multiple modular stators includes three partitions, each partition is equipped with an armature, and the armature parameters in formula (3) are as follows: , , , , , , , , , , , . Assume that the target signal that the motor speed needs to track is:

[0101] .

[0102] According to steps S1-S4 described in this embodiment, the current and speed signals are detected, the current deviation is calculated, a control signal is generated and applied to the motor, and the current equalization thermal balance effect of the motor is obtained as follows: Figure 3 As shown, in which, in the time period of 0-15 seconds, the method for updating the control weight matrix according to the current deviation in steps S401 and S402 is not adopted (part of the method of this embodiment is used). At this time, the motor does not consider the current sharing thermal balance in the process of tracking the target speed. The results show that the motor can track the target speed, but the current deviation of armature 1-3 is large. From 15 seconds on, the current sharing method is adopted (performed according to steps S1-S4 of this embodiment). At this time, the motor not only accurately tracks the target speed, but the current of armature 1-3 also converges rapidly. At 30 seconds, when the target signal changes, the motor speed can still respond and track quickly, and the current of armature 1-3 also quickly converges after a short oscillation.

[0103] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for heat balance of current distribution of a deep-sea robot driving motor, characterized in that: The steps include: Step S1, considering a DC motor with n modular stators, constructing a set of differential equations describing the input and output characteristics of the motor, covering both the mechanical part and the electrical part, for comprehensively describing the dynamic behavior of the motor; Step S2, measuring the current value of each armature and the motor speed in real time, and calculating the standard deviation of the current and the current difference between each armature; Step S3, constructing a parameter matrix required for calculating the control gain and a solution matrix for calculating the control signal, and constructing a control weight matrix and a weight adjustment coefficient for dynamically calculating the control signal; Step S4, based on the calculated standard deviation and current difference, the control weight matrix is ​​updated in real time at a certain period, the solution matrix is ​​updated iteratively, the control voltage signal is calculated and applied to each armature.

2. A method for heat balance of a deep-sea robot driving motor according to claim 1, characterized in that: The step S1 comprises the following steps: Step S101, construct variables and parameters describing the dynamic characteristics of the motor, variables Indicates motor output, variable represents the induced current of the jth armature, and the variable It represents the control voltage signal of the jth armature input, and the parameter is the resistance of the jth armature, parameter is the inductance of the jth armature, parameter is the viscous friction coefficient of the motor, and the parameter is the armature constant of the jth armature, is the electromotive force constant of the jth armature, for the jth armature, j=1,2,…,n; Step S102, construct the mechanical part of the motor equation, according to the motor inertia load J multiplied by the derivative of the angular velocity equal to the sum of all torques of the motor shaft, to obtain the following equation: (1) In formula (1), It is a derivative operator, which means the derivative of a variable with respect to time t; Step S103, constructing the electrical part of the motor equation, and obtaining the following equation according to the relationship between the applied voltage, induced electromotive force, resistance voltage and inductance voltage of each armature: (2) In formula (2), is the induced electromotive force of the jth armature; Step S104, construct a differential equation group describing the motor behavior. Based on equation (1) and equation (2), the differential equation describing the motor behavior can be obtained: (3) In formula (3), the first row of equations is used to describe the applied voltage With the induction current The relationship between the second row of equations is used to describe the induced current Angular velocity of motor shaft The relationship between.

3. A method for heat balance of a deep-sea robot driving motor according to claim 1, characterized in that: The step S2 comprises the following steps: Step S201, real-time measurement of the current value of each armature in the motor , ( j = 1, 2, ..., n) and motor speed ; Step S202, calculate the average current of each armature ; Step S203, calculating the standard deviation of the current of each armature ,symbol Indicates absolute value; Step S204, calculating the difference between the armature currents , k=1,2,…,n, .

4. A method for heat balance of a deep-sea robot driving motor according to claim 1, characterized in that: The step S3 comprises the following steps: Step S301: construct the parameter matrix required for calculating the control gain , and , ， ， ， ， ， ， ， , , where diag(V) means generating a diagonal matrix with vector V as the diagonal element. Represents the transpose operation of a matrix or vector; Step S302, construct an iterative solution matrix for calculating the control signal, construct Dimensional real iterative solution matrix And assign initial values ​​to make it positive definite or semi-positive definite; Step S303: construct a control weight matrix , build dimensional real positive definite matrix And assign initial value ,in, represent dimensional identity matrix; Step S304: construct weight adjustment coefficient , construct positive real numbers And assign a value.

5. A method for heat balance of a deep-sea robot driving motor according to claim 1, characterized in that: The step S4 comprises the following steps: Step S401, calculate the current deviation matrix according to a certain period , (4) Step S402: Update the control weight matrix at a certain period. The value of is updated to ; Step S403, when the control weight matrix When the value of is updated, iterative calculation is performed and the iterative solution matrix is ​​updated according to formula (5) The numerical value of (5) In formula (5), Represents the solution matrix The value after completing the kth iteration; Step S404, after each iteration, calculate and The difference between the two, check the convergence conditions (6) If the convergence condition in equation (6) is not met, then return to step S403 and continue iterating. If the convergence condition is met, then stop iterating and output , in formula (6), is a preset small positive number to determine whether the solution converges. represents the matrix norm; Step S405, calculate the control signal according to formula (7) (7) in, , , is the set motor speed target signal; Step S406: The voltage signal calculated in equation (7) is Drive each armature and return to step S401.

Images