A method for zero-torque and torque zero-crossing control of a drive motor

Abstract

The application relates to a zero-torque and torque-zero control method of a driving motor, and the main steps are as follows: when the torque demand of the driving motor changes from zero to positive torque, and the torque demand is less than or equal to A, the torque execution value of the motor controller is kept as A; when the torque demand is greater than A, the torque execution value of the motor controller is the torque demand value; when the torque demand of the driving motor changes from positive to zero or to negative, and the torque demand is less than or equal to A and greater than or equal to -B, the torque execution value of the motor controller is kept as A; when the torque demand is greater than A or less than -B, the torque execution value of the motor controller is the torque demand value; when the torque demand of the driving motor changes from negative to zero or to positive, and the torque demand is greater than -B and less than A, the torque execution value of the motor controller is kept as -B; when the torque demand is greater than A or less than -B, the torque execution value of the motor controller is the torque demand value; the application can avoid the noise caused by repeated knocking and reduce the wear between the splines.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicle motor control, more particularly to a zero-torque and torque zero-crossing control method for driving motor. BACKGROUND

[0002] At present, with the decrease of petrochemical energy reserves and the requirement of carbon neutralization, the state and the world have a series of policies to encourage the development and development of new energy vehicles. The output torque of the driving motor of the new energy vehicle has unavoidable torque ripple, which will cause the phenomenon of repeated tooth knocking at the zero torque working condition and the zero crossing working condition (such as Figure 2 ), which will produce repeated knocking noise, affecting the comfort of the driver and the passenger.

[0003] The traditional method to reduce the noise caused by repeated tooth knocking is to modify the spline or gear tooth shape to reduce the gap of the matching tooth surface, but the gap of the spline or gear is too small for assembly, and it is also impossible to completely avoid the repeated knocking sound. SUMMARY

[0004] In order to solve the above technical problems, the purpose of the present application is to provide a zero-torque and torque zero-crossing control method for driving motor, which can avoid the problem of repeated tooth knocking at zero torque and torque zero-crossing moment, reduce the corresponding knocking noise, and improve the comfort of the driver and the passenger.

[0005] In order to achieve the above-mentioned purpose of the application, the following technical solutions are adopted:

[0006] A zero-torque and torque zero-crossing control method for driving motor, which is realized by a program in the motor controller, comprising the following steps:

[0007] Step 1: preset the required torque zero-crossing interval as [-B, A], and A>0, B>0;

[0008] Step 2: determine whether the driving motor has zero-crossing working condition or zero-torque requirement, if not, the motor controller torque execution value is executed according to the torque requirement value given by the vehicle controller, if yes, execute step 3;

[0009] Step 3: determine whether the torque requirement of the driving motor is from zero to positive torque, if yes and the torque requirement is less than or equal to A, the motor controller torque execution value is kept as A, if yes and the torque requirement is greater than A, the motor controller torque execution value is the torque requirement value; if not, execute step 4;

[0010] Step 4: judging whether the torque demand of the driving motor is from positive to zero or to negative, if yes and the torque demand is less than or equal to A and greater than or equal to -B, the torque execution value of the motor controller is kept as A, if yes and the torque demand is greater than A or less than -B, the torque execution value of the motor controller is the torque demand value; if no, step 5 is executed;

[0011] Step 5: judging whether the torque demand of the driving motor is from negative to zero or to positive, if yes and the torque demand is greater than -B and less than A, the torque execution value of the motor controller is kept as -B, if yes and the torque demand is greater than A or less than -B, the torque execution value of the motor controller is the torque demand value; if no, step 2 is executed.

[0012] As a preferred solution, A and B in step 1 are adjustable values, and are preset as A=B=0.5.

[0013] As a preferred solution, the zero torque working condition in step 2 refers to zero torque demand, and the zero torque passing condition includes zero torque to positive torque operation and zero torque to negative torque operation, positive torque to negative torque zero passing and negative torque to positive torque zero passing.

[0014] As a preferred solution, the demand torque in step 3 is given to the motor controller by the vehicle controller, and the motor output torque is equal to the torque execution value of the motor controller.

[0015] As a preferred solution, the controller execution torque in step 3 is executed according to the demand value of the vehicle controller, and the controller execution torque and the demand torque of the vehicle controller have the following relationship: -B<demand torque<A, the execution torque=A or the execution torque=-B; demand torque>=A, the execution torque=demand torque; demand torque<=-B, the execution torque=demand torque.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] Compared with the prior art, the present application has the following beneficial effects:

[0018] The present application sets adjustable zero torque and zero passing region, and executes fixed torque value in the region, which avoids repeated tooth knocking phenomenon, reduces corresponding tooth knocking noise, reduces the influence of noise on the comfort of drivers and passengers, and further reduces the wear between splines. The method of the present application is more economical and reliable than the traditional modification of tooth shape. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the application, and are incorporated in and constitute a part of this specification, the illustrative embodiments of the application, and their description, serve the purpose of explanations without limiting the application.

[0020] Figure 1 Flow chart of the control method of the application;

[0021] Figure 2 Example of the rattle phenomenon caused by the torque ripple mentioned in the application;

[0022] Figure 3 Schematic diagram of avoiding the rattle phenomenon after adopting the zero torque and zero-crossing torque control method mentioned in the application;

[0023] Figure 4 Comparison diagram of the motor output torque and the torque demand given by the vehicle controller after adopting the method of the application. DETAILED DESCRIPTION

[0024] It should be noted that the following detailed description is illustrative only, and is intended to provide further description in addition to the description of the exemplary embodiments according to the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0025] It should be noted that the terms used herein are only intended to describe specific embodiments and are not intended to limit the exemplary embodiments according to the application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should be understood that when the terms "comprise" and / or "include" are used in this specification, there is a feature, step, operation, device, component and / or combination thereof.

[0026] In addition, in the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0027] In addition, the terms "first", "second", etc. are used only for descriptive purposes and should not be construed as indicating or implying relative importance or an indicated number of the technical features indicated. Thus, the features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specified or limited.

[0028] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0029] In the present application, unless otherwise explicitly specified and limited, "on" or "under" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, "on", "above" and "above" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0030] The present application will be further described below in conjunction with the drawings and embodiments:

[0031] As shown in Figure 1 , Figure 4 and Figure 3 A zero-torque and zero-torque control method of a driving motor, which is realized by a program in a motor controller, comprising the following steps:

[0032] Step 1: preset the zero-torque interval of the required torque as [-B, A], and A>0, B>0; as preferred, A and B are both adjustable values, and are preset as A=B=0.5.

[0033] Step 2: determine whether the driving motor has a zero-crossing working condition or a zero-torque requirement, if not, the motor controller torque execution value is executed according to the torque requirement value given by the vehicle controller, if yes, execute step 3;

[0034] Wherein, zero torque condition refers to zero torque demand, and torque zero-crossing condition includes zero torque to positive torque operation and zero torque to negative torque operation when the driving motor starts, positive torque to negative torque zero-crossing, and negative torque to positive torque zero-crossing.

[0035] Step 3: Determine whether the torque demand of the driving motor is from zero to positive torque, if yes and the torque demand is less than or equal to A, the torque execution value of the motor controller is kept as A, if yes and the torque demand is greater than A, the torque execution value of the motor controller is the torque demand value, if not, step 4 is executed.

[0036] Step 4: Determine whether the torque demand of the driving motor is from positive to zero or to negative, if yes and the torque demand is less than or equal to A and greater than or equal to -B, the torque execution value of the motor controller is kept as A, if yes and the torque demand is greater than A or less than -B, the torque execution value of the motor controller is the torque demand value, if not, step 5 is executed.

[0037] Step 5: Determine whether the torque demand of the driving motor is from negative to zero or positive, if yes and the torque demand is greater than -B and less than A, the torque execution value of the motor controller is kept as -B, if yes and the torque demand is greater than A or less than -B, the torque execution value of the motor controller is the torque demand value, if not, step 2 is executed.

[0038] In step 3, the demand torque from zero to positive corresponds to the torque demand value from zero to positive after the motor controller jumps from standby mode to torque mode each time.

[0039] In step 3, the torque demand is given by the vehicle controller to the motor controller, and the motor output torque is equal to the torque execution value of the motor controller.

[0040] In step 3, the controller execution torque is executed according to the demand value of the vehicle controller, and the controller execution torque and the demand torque of the vehicle controller have the following relationship: -B<demand torque<A, the execution torque=A or the execution torque=-B; demand torque>=A, the execution torque=demand torque; demand torque<=-B, the execution torque=demand torque.

[0041] The following provides a specific embodiment as a reference.

[0042] A driving motor zero torque and torque zero-crossing control method, comprising the following steps:

[0043] Step 1: The motor controller MCU receives the torque demand instruction of the vehicle controller, and determines whether there is zero torque demand or zero-crossing torque demand. (The preset demand torque zero-crossing interval [-B, A] is set when the motor is manufactured, and does not need to be set again in later use of the motor).

[0044] Step 2: When the motor controller MCU receives a zero-torque demand or a zero-crossing torque demand, it determines the trend of the torque demand;

[0045] Step 3: If the torque demand trend received by the motor controller MCU is that the starting torque is 0 and the subsequent torque is positive, when the torque demand is [0, A], the motor controller gives a torque execution instruction of A; when the torque demand is > A, the torque execution value = torque demand value;

[0046] Step 4: If the torque demand trend received by the motor controller MCU is that the starting torque is 0 and the subsequent torque is negative, when the torque demand is [-B, 0], the motor controller gives a torque execution instruction of -B, and when the torque demand is <-B, the torque execution value = torque demand value;

[0047] Step 5: If the torque demand trend received by the motor controller MCU is that the torque changes from positive to 0 or negative, when the torque demand is > A, the torque execution value = torque demand value; when the torque demand is in the [-B, A] region, the torque execution value is A; and when the torque demand is <-B, the torque execution value = torque demand value;

[0048] Step 6: If the torque demand trend received by the motor controller MCU is that the torque changes from negative to 0 or positive, when the torque demand is <-B, the torque execution value = torque demand value; when the torque demand is in the [-B, A] region, the torque execution value is -B; and when the torque demand is > A, the torque execution value = torque demand value;

[0049] By implementing the zero-torque and torque zero-crossing control method for the driving motor of the new energy vehicle, the phenomenon of repeated knocking of the shaft teeth due to torque ripple is avoided, thereby reducing the corresponding noise.

[0050] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0051] Although the embodiments of the present application have been shown and described above, it is to be understood that the above embodiments are merely exemplary and are not to be taken as limiting the present application, and that within the principles and scope of the present application, those skilled in the art can make changes, modifications, replacements and variations to the above embodiments without departing from the principles and spirit of the present application, and any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application still falls within the scope of the technical scheme of the present application.

Claims

1. A method for controlling zero torque and zero torque crossing of a drive motor, the method being implemented by a program within a motor controller, characterized in that, It includes the following steps: Step 1: Preset the zero-crossing interval of the required torque as [-B, A], where A > 0 and B > 0; Step 2: Determine whether the drive motor has a zero-crossing condition or a zero-torque requirement. If not, the torque execution value of the motor controller is executed according to the torque requirement value given by the vehicle controller. If so, proceed to Step 3; Step 3: Determine whether the torque requirement of the drive motor changes from zero to positive torque. If so and the torque requirement is less than or equal to A, the torque execution value of the motor controller remains A. If so and the torque requirement is greater than A, the torque execution value of the motor controller is the torque requirement value. If not, proceed to Step 4; Step 4: Determine whether the torque requirement of the drive motor changes from positive to zero or negative. If so and the torque requirement is less than or equal to A and greater than or equal to -B, the torque execution value of the motor controller remains A. If so and the torque requirement is greater than A or less than -B, the torque execution value of the motor controller is the torque requirement value. If not, proceed to Step 5; Step 5: Determine whether the torque requirement of the drive motor changes from negative to zero or positive. If so and the torque requirement is greater than -B and less than A, the torque execution value of the motor controller remains -B. If so and the torque requirement is greater than A or less than -B, the torque execution value of the motor controller is the torque requirement value. If not, proceed to Step 2.

2. The method for controlling zero torque and zero torque crossing of a drive motor according to claim 1, characterized in that, A and B in Step 1 are calibrated and adjustable values, preset as A = B = 0.

5.

3. The method for controlling zero torque and zero torque crossing of a drive motor according to claim 1, characterized in that, The zero-torque condition in Step 2 refers to zero-torque requirement. The torque zero-crossing conditions include the operation of the drive motor from zero torque to positive torque and from zero torque to negative torque during startup, as well as the zero-crossing from positive torque to negative torque and from negative torque to positive torque.

4. The method for controlling zero torque and zero torque crossing of a drive motor according to claim 1, characterized in that, In Step 3, when the required torque changes from zero to positive, it corresponds to the process where the torque requirement value changes from zero to positive after the motor controller jumps from the standby mode to the torque mode each time.

5. The method for controlling zero torque and zero torque crossing of a drive motor according to claim 1, characterized in that, In Step 3, the torque requirement is given by the vehicle controller to the motor controller, and the motor output torque is equal to the torque execution value of the motor controller.

6. A method for controlling zero torque and zero torque crossing of a drive motor according to claim 1, characterized in that, The controller executes the torque according to the requirement value of the vehicle controller. The relationship between the controller-executed torque and the vehicle controller's required torque is as follows: when -B < required torque < A, executed torque = A or executed torque = -B; when required torque >= A, executed torque = required torque; when required torque <= -B, executed torque = required torque.

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