Methods, apparatuses, media, and products for determining range extender moment of inertia

Abstract

The present disclosure provides a method, device, medium and product for determining the moment of inertia of a range extender, which can be applied to the technical field of moment of inertia testing. The method comprises: under the condition that the engine inside the range extender is maintained to be fuel cut, dragging the range extender to a first stable state by a motor and obtaining first state data of the first stable state; continuing to drag the range extender from the first stable state to a second stable state by the motor with a predetermined step torque applied, and obtaining second state data of the second stable state and an actual step torque generated by the motor under the predetermined step torque, wherein a first rotational speed difference between the second stable state and the first stable state is less than a predetermined value; selecting a target stage during the period from the first stable state to the second stable state, and determining the moment of inertia of the range extender according to the starting state data, the ending state data, the first state data, the second state data and the actual step torque of the target stage.

Description

Technical Field

[0001] This disclosure relates to the field of rotational inertia testing technology, and more specifically to a method, apparatus, medium, and product for determining the rotational inertia of a range extender. Background Technology

[0002] Moment of inertia is a physical quantity that describes the magnitude of an object's inertia when rotating about an axis. Its value depends on the object's mass distribution and the position of the axis of rotation. In range extender design, accurately measuring the range extender's moment of inertia is crucial. Moment of inertia directly affects the range extender's start-stop and acceleration / deceleration performance, vibration characteristics, and the vehicle's dynamic response. It is a prerequisite for engineering projects such as vehicle road simulation and flywheel design, and plays a fundamental role in the dynamic matching and control strategy optimization of the vehicle control system.

[0003] Currently, there are three main methods for determining the moment of inertia of range extenders. The first method is theoretical calculation based on precise numerical models and material parameters, but this is usually not easy. Another method involves disassembling the range extender for measurement, which may damage it. A third method measures the moment of inertia through system identification. However, existing system identification methods (such as the fuel cut-off free deceleration method) not only require precision instruments, making them expensive, but also rely on measurement data over a large range of speed differences. Within this range, the nonlinear characteristics of the system resistance torque are significant, leading to large errors in determining the moment of inertia and making it difficult to guarantee the accuracy of the measurement. Summary of the Invention

[0004] In view of the above problems, this disclosure provides non-destructive methods, apparatus, media and products for determining the moment of inertia of a range extender, which improves the accuracy of moment of inertia measurement while reducing measurement costs.

[0005] One aspect of this disclosure provides a method for determining the moment of inertia of a range extender, comprising: dragging the range extender to a first stable state by means of a motor while maintaining fuel cut-off in the engine inside the range extender, and acquiring first state data of the first stable state; continuing to drag the range extender from the first stable state to a second stable state by means of a motor with a predetermined step torque applied, and acquiring second state data of the second stable state, and the actual step torque generated by the motor under the predetermined step torque, wherein a first speed difference between the second stable state and the first stable state is less than a predetermined value; selecting a target stage during the period from the first stable state to the second stable state, and determining the moment of inertia of the range extender based on the start state data, end state data, first state data, second state data and actual step torque of the target stage.

[0006] According to embodiments of this disclosure, determining the rotational inertia of the range extender based on the initial state data, final state data, first state data, second state data, and actual step torque of the target stage includes: determining the rate of change of the range extender's resistance torque with rotational speed based on the first state data and second state data; determining the equivalent resultant torque and mean angular acceleration of the range extender in the target stage based on the rate of change of the resistance torque with rotational speed, the actual step torque of the motor, the initial state data of the target stage, the final state data of the target stage, and the first state data; and obtaining the rotational inertia of the range extender based on the ratio of the equivalent resultant torque to the mean angular acceleration.

[0007] According to embodiments of this disclosure, the first state data includes a first speed value of the range extender and a first actual torque value of the motor, and the second state data includes a second speed value of the range extender and a second actual torque value of the motor. Determining the rate of change of the resistance torque of the range extender with respect to speed based on the first and second state data includes: obtaining the actual torque deviation of the motor based on the first and second actual torque values; and obtaining the rate of change of the resistance torque with respect to speed based on the ratio of the actual torque deviation to the speed difference between the second and first speed values.

[0008] According to embodiments of this disclosure, the first state data and the second state data are obtained as follows: a first original rotational speed signal and a first original torque signal are acquired under a first stable state, and a second original rotational speed signal and a second original torque signal are acquired under a second stable state; the first original rotational speed signal, the first original torque signal, the second original rotational speed signal, and the second original torque signal are filtered to obtain a first target rotational speed signal, a first target torque signal, a second target rotational speed signal, and a second target torque signal; the rotational speed fluctuation value of the first target rotational speed signal and the second target rotational speed signal, as well as the torque fluctuation value of the first target torque signal and the second target torque signal, are less than a predetermined threshold within a first predetermined time period; based on the characteristic values ​​of the first target rotational speed signal, the first target torque signal, the second target rotational speed signal, and the second target torque signal, a first rotational speed value, a first actual torque value, a second rotational speed value, and a second actual torque value are obtained, respectively.

[0009] According to embodiments of this disclosure, determining the equivalent resultant torque and average angular acceleration of the range extender in the target stage based on the rate of change of the resistance torque with rotational speed, the actual step torque of the motor, the initial state data of the target stage, the final state data of the target stage, and the first state data includes: determining the average angular acceleration of the range extender in the target stage based on the initial state data and the final state data of the target stage; determining the second speed difference between the first stable state and the target stage based on the initial state data, the final state data of the target stage, and the first state data; determining the equivalent resistance torque of the range extender in the target stage based on the rate of change of the resistance torque with rotational speed and the second speed difference; and obtaining the equivalent resultant torque of the range extender in the target stage based on the equivalent resistance torque and the actual step torque of the motor.

[0010] According to embodiments of this disclosure, the initial state data includes an initial time and an initial rotational speed; the final state data includes an final time and a final rotational speed; determining the average angular acceleration of the range extender in the target stage based on the initial state data and the final state data of the target stage includes: obtaining a third rotational speed difference of the range extender in the target stage based on the difference between the initial rotational speed value and the final rotational speed value; and obtaining the average angular acceleration based on the ratio of the third rotational speed difference to the time difference between the initial time and the final time.

[0011] This disclosure also provides an apparatus for determining the moment of inertia of a range extender, comprising: a first acquisition module, configured to, while maintaining fuel cut-off in the engine inside the range extender, drag the range extender to a first stable state via a motor, and acquire first state data of the first stable state; a second acquisition module, configured to, using a motor with a predetermined step torque applied, continue to drag the range extender from the first stable state to a second stable state, and acquire second state data of the second stable state, as well as the actual step torque generated by the motor under the predetermined step torque, wherein a first speed difference between the second stable state and the first stable state is less than a predetermined value; and a first determination module, configured to, during the period from the first stable state to the second stable state, select a target stage, and determine the moment of inertia of the range extender based on the start state data, end state data, first state data, second state data, and actual step torque of the target stage.

[0012] Another aspect of this disclosure provides an electronic device comprising: one or more processors; and a memory for storing one or more computer programs, wherein the one or more processors execute the one or more computer programs to implement the steps of the method according to any one of claims 1 to 7.

[0013] Another aspect of this disclosure provides a computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implement the steps of the above-described method.

[0014] Another aspect of this disclosure provides a computer program product, including a computer program or instructions that, when executed by a processor, implement the steps of the above-described method.

[0015] According to embodiments of this disclosure, while maintaining fuel cutoff in the range extender's internal engine, the range extender is first dragged to a first stable state by a motor, and first state data is acquired. Then, a predetermined step torque is applied to the motor to continue dragging the range extender to a second stable state, and second state data is acquired. The amplitude of the predetermined step torque is controlled to limit the speed difference between the second and first stable states to a small range (e.g., 100 rpm). Next, during the dynamic process from the first to the second stable state, a target stage is selected where the range extender's speed changes linearly with time. Finally, based on the start and end data of this target stage and the data from the two stable states, the moment of inertia of the range extender is determined. Because the process of determining the range extender's moment of inertia is limited to a small speed difference range, within which the resistance torque changes linearly with the speed, errors caused by nonlinear changes in resistance torque over a large speed range can be avoided, thereby improving the measurement accuracy of the moment of inertia. On the other hand, the measurement process of this embodiment utilizes the existing drive motor and measurement sensors in the system, eliminating the need for additional precision measurement equipment and complex instruments, thus reducing measurement costs and complexity. Moreover, it eliminates the need to disassemble the range extender, achieving non-destructive measurement of rotational inertia, and has the potential for real-time online application in vehicle controllers or production line off-line testing systems. Attached Figure Description

[0016] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0017] Figure 1 The illustration schematically depicts an application scenario for determining the moment of inertia of a range extender according to an embodiment of the present disclosure.

[0018] Figure 2 A flowchart illustrating a method for determining the moment of inertia of a range extender according to an embodiment of the present disclosure is shown schematically.

[0019] Figure 3 A flowchart illustrating a method for determining the moment of inertia of a range extender according to another embodiment of the present disclosure is shown schematically.

[0020] Figure 4 The diagram illustrates the changes in torque, rotational speed, and angular velocity over time according to an embodiment of the present disclosure.

[0021] Figure 5A schematic block diagram of a device for determining the moment of inertia of a range extender according to an embodiment of the present disclosure is shown.

[0022] Figure 6 A block diagram schematically illustrates an electronic device suitable for implementing a method for determining the moment of inertia of a range extender, according to an embodiment of the present disclosure. Detailed Implementation

[0023] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0024] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0025] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0026] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0027] Currently, the measurement of the rotational inertia of traditional range extenders can be divided into numerical model calculation and measurement methods. The numerical model calculation method requires accurate numerical models of all components of the range extender and various material parameters, which is usually not easy. Measurement methods can be further divided into direct component measurement methods and system identification methods. Traditional direct component measurement methods include the trilinear pendulum method, compound pendulum method, torsional pendulum method, and constant torque rotation method (falling body method). However, direct measurement requires disassembling the range extender, which may cause damage. Furthermore, the range extender consists of many complex-shaped components, making it difficult to accurately measure the rotational inertia of each component. In addition, the complex assembly relationships make it difficult to calculate the overall equivalent rotational inertia even if the inertia of each component is known. Moreover, when measuring rotational inertia, the transient process must consider not only the inertia of the rigid body but also the inertia of the fluid, which neither the numerical model calculation method nor direct measurement can cover. Therefore, in practical work, the system identification method can be used to measure the rotational inertia.

[0028] Regarding the measurement of rotational inertia through system identification, it can be achieved using a test bench based on the added mass method; it can also be based on instantaneous rotational speed measurement of rotational inertia; it can also be achieved using a test bench device that applies reverse torque to the engine through an electric motor and calculates the engine's rotational inertia using the law of conservation of energy; it can also be based on the acceleration value and the torque received during acceleration and deceleration, using formulas to calculate the rotational inertia of each component; it can also be based on a rotational inertia test method that fits the entire range of deceleration with fuel cut-off; it can also be based on a method that measures the rotational inertia of the entire vehicle during rapid acceleration and deceleration at full throttle, but the actual torque in this method comes from the torque model calibrated within the controller, which may have some deviation.

[0029] Based on the above measurement methods, the addition mass method and instantaneous speed measurement method are complex and require precise instruments, such as high-precision torque sensors and cylinder pressure sensors, and cannot be applied to actual vehicles. The method of calculating the moment of inertia of each component using formulas based on the acceleration value and torque experienced during acceleration and deceleration does not consider the coupling between moment of inertia and resistance torque, and cannot eliminate the influence of resistance torque, resulting in errors. The instantaneous speed method, fuel cut-off deceleration method, and acceleration / deceleration method rely on accurate resistance torque, but the resistance torque in the dynamic process is not easy to obtain accurately, making it difficult to guarantee calculation accuracy. The addition mass method, fuel cut-off deceleration method, and acceleration / deceleration method obtain average values ​​of a wide range of speeds. Since moment of inertia is related to crankshaft angle and speed, there is also a deviation between the moment of inertia measured over a wide range of speeds and the actual value. Furthermore, all of the above methods require post-processing of the test data to obtain the moment of inertia, making real-time application impossible. Based on the shortcomings of existing methods, such as difficulty in real-time application, inaccurate resistance torque, and excessively large speed range, this disclosure proposes a highly accurate method for measuring moment of inertia within a small speed range based on step torque, which can be applied in real-time.

[0030] Figure 1The illustration schematically depicts an application scenario for determining the moment of inertia of a range extender according to an embodiment of the present disclosure.

[0031] like Figure 1 As shown, the application scenario 100 according to this embodiment may include a range extender 101, a motor 102, and a controller 103.

[0032] The controller 103 can control the motor 102 to drag the range extender 101 to a stable state. For example, it can control the motor to drag the range extender 101 to a first stable state. The controller 103 can also apply a predetermined step torque to the motor 102 and control the motor 102 with the predetermined step torque applied to drag the range extender 101 to a second stable state.

[0033] The controller 103 may also be equipped with sensors that can be used to measure the state data of the range extender 101 in a stable state, such as the first state data in a first stable state and the second stable data in a second stable state. The sensors can also measure the actual torque value of the motor.

[0034] The controller 103 is also used to calculate the moment of inertia of the range extender 101 based on the first state data and the second state data measured by the sensor, combined with the target stage data of linear change of rotational speed with time from the first stable state to the second stable state.

[0035] It should be understood that Figure 1 The number of range extenders 101, motors 102, and controllers 103 shown is merely illustrative. Any number of range extenders 101, motors 102, and controllers 103 can be used depending on implementation requirements.

[0036] The following will be based on Figure 1 The described scene, through Figures 2-4 A method for determining the moment of inertia of a range extender according to a disclosed embodiment will be described in detail.

[0037] Figure 2 A flowchart illustrating a method for determining the moment of inertia of a range extender according to an embodiment of the present disclosure is shown schematically.

[0038] like Figure 2 As shown, the method for determining the moment of inertia of the range extender in this embodiment includes operations S210 to S230.

[0039] In operation S210, while maintaining the engine fuel cut-off inside the range extender, the range extender is dragged to the first stable state by the motor, and the first state data of the first stable state is acquired.

[0040] In some embodiments, maintaining the engine fuel cut-off inside the range extender can prevent the engine from generating combustion power, thereby avoiding errors in the measurement of rotational inertia caused by the combustion torque of the engine.

[0041] The first stable state can refer to the range extender's speed changing less than a predetermined speed within a first predetermined time period, and the motor's torque signal changing less than a predetermined torque within a second predetermined time period. The first and second predetermined time periods can be the same or different, and the first, second, predetermined time periods, predetermined speed, and predetermined torque can all be adaptively adjusted according to actual needs.

[0042] The first status data may include the first speed value of the range extender. and the first actual torque value of the motor In one embodiment, the actual torque of the motor in a steady state is equal in magnitude but opposite in sign to the resistance torque in the same steady state, for example, , The actual torque of the motor under steady-state conditions. This represents the resistance torque under steady-state conditions.

[0043] In operation S220, the range extender is continued to be dragged from the first stable state to the second stable state by a motor with a predetermined step torque applied, and the second state data of the second stable state and the actual step torque generated by the motor under the predetermined step torque are acquired, wherein the first speed difference between the second stable state and the first stable state is less than a predetermined value.

[0044] In some embodiments, a predetermined step torque This can be used to limit the first speed difference between the second stable state and the first stable state to a small predetermined value, such as 100 rpm. The predetermined step torque value must be appropriately selected to ensure the resulting speed difference remains within a small range. An excessively large speed difference will cause a deviation between the actual change in resistance torque and the preset linear change in resistance torque with speed; an excessively small speed difference will result in no obvious linear change range of resistance torque with speed. The predetermined step torque can be related to the engine specifications. For example, with a 2.5L engine, the predetermined step torque can be 10~15 N·m, preferably 12.67 N·m.

[0045] The second stable state can refer to the range extender's speed changing by less than a predetermined speed within a first predetermined time period, and the motor's torque signal changing by less than a predetermined torque within a second predetermined time period. The second state data under the second stable state can include the range extender's second speed value. and the second actual torque value of the motor .

[0046] In some embodiments, the predetermined step torque of the motor It should be consistent with the actual step torque of the motor. If they are equal, then the actual step torque of the motor shall prevail. To determine the standard, the moment of inertia is measured and calculated. It can be the actual torque value of the motor under the condition of applying a predetermined step torque and in the third steady state, and The difference, the third stable state can be between the first stable state and the second stable state, and the torque fluctuation value of the motor is less than the predetermined torque value within a predetermined time period.

[0047] In operation S230, a target stage is selected during the transition from the first stable state to the second stable state, and the moment of inertia of the range extender is determined based on the start state data, end state data, first state data, second state data, and actual step torque of the target stage.

[0048] In some embodiments, the target stage can be a stage where the angular acceleration is relatively stable and the rotational speed changes approximately linearly with time.

[0049] The initial state data for the target phase may include the start time. Starting speed The termination status data for the target phase may include the termination time. Terminate speed .make , ;Depend on Average angular acceleration during the period With equivalent resultant torque The moment of inertia of the range extender was calculated. , , , This represents the linear rate of change of the resistance torque with respect to rotational speed.

[0050] According to embodiments of this disclosure, while maintaining fuel cutoff in the range extender's internal engine, the range extender is first dragged to a first stable state by a motor, and first state data is acquired. Then, a predetermined step torque is applied to the motor to continue dragging the range extender to a second stable state, and second state data is acquired. The amplitude of the predetermined step torque is controlled to limit the speed difference between the second and first stable states to a small range (e.g., 100 rpm). Next, during the dynamic process from the first to the second stable state, a target stage is selected where the range extender's speed changes linearly with time. Finally, based on the start and end data of this target stage and the data from the two stable states, the moment of inertia of the range extender is determined. Because the process of determining the range extender's moment of inertia is limited to a small speed difference range, within which the resistance torque changes linearly with the speed, errors caused by nonlinear changes in resistance torque over a large speed range can be avoided, thereby improving the measurement accuracy of the moment of inertia. On the other hand, the measurement process of this embodiment utilizes the existing drive motor and measurement sensors in the system, eliminating the need for additional precision measurement equipment and complex instruments, thus reducing measurement costs and complexity. Moreover, it eliminates the need to disassemble the range extender, achieving non-destructive measurement of rotational inertia, and has the potential for real-time online application in vehicle controllers or production line off-line testing systems.

[0051] In some embodiments, the first state data and the second state data can be obtained respectively by: acquiring the first original speed signal and the first original torque signal in the first stable state, and acquiring the second original speed signal and the second original torque signal in the second stable state; filtering the first original speed signal, the first original torque signal, the second original speed signal, and the second original torque signal to obtain the first target speed signal, the first target torque signal, the second target speed signal, and the second target torque signal, wherein the speed fluctuation value of the first target speed signal and the second target speed signal, and the torque fluctuation value of the first target torque signal and the second target torque signal are less than a predetermined threshold within a first predetermined time period; and obtaining the first speed value, the first actual torque value, the second speed value, and the second actual torque value based on the feature values ​​of the first target speed signal, the first target torque signal, the second target speed signal, and the second target torque signal.

[0052] In some embodiments, the original speed signal is the signal of the range extender's speed changing over time, and the original torque signal is the signal of the motor's torque changing over time. If any wave of the first original speed signal, the first original torque signal, the second original speed signal, or the second original torque signal in the first stable state exhibits significant fluctuations (speed fluctuation value greater than a predetermined speed, or torque fluctuation value greater than a predetermined torque), the signal with significant fluctuations (e.g., the first original speed signal) can be filtered. If the speed fluctuation value of the target signal (e.g., the first target speed signal) obtained after filtering is less than the predetermined speed, the characteristic value of the first target speed signal (e.g., the average value of the stable wave band, or the steady-state value at the end of the signal) is used as the first state data or the second state data (e.g., the steady-state value at the end of the signal of the first target speed signal is used as the first speed value in the first state). ).

[0053] According to embodiments of this disclosure, by filtering the original signal, the accuracy of the first state data and the second state data can be ensured, providing high-precision support for the calculation of moment of inertia. Moreover, by filtering, electromagnetic interference and abnormal wave signals caused by instantaneous sensor anomalies can be filtered out, thereby improving the accuracy of moment of inertia calculation.

[0054] In some embodiments, the process of determining the moment of inertia of the range extender based on the initial state data, final state data, first state data, second state data, and actual step torque of the target stage may include the following operations: determining the rate of change of the range extender's resistance torque with respect to rotational speed based on the first state data and second state data; determining the equivalent resultant torque and mean angular acceleration of the range extender in the target stage based on the rate of change of the resistance torque with respect to rotational speed, the actual step torque of the motor, the initial state data of the target stage, the final state data of the target stage, and the first state data; and obtaining the moment of inertia of the range extender based on the ratio of the equivalent resultant torque to the mean angular acceleration.

[0055] The process of determining the rate of change of the range extender's resistance torque with respect to rotational speed based on the first state data and the second state data may include the following operations: obtaining the actual torque deviation of the motor based on the first actual torque value and the second actual torque value; obtaining the rate of change of the resistance torque with respect to rotational speed based on the ratio of the actual torque deviation to the speed difference between the first speed value and the second speed value.

[0056] Based on the first and second actual torque values, the actual torque deviation between the motor's stable states is obtained, i.e. .

[0057] Based on the actual torque deviation and the second speed value and the first speed value Speed ​​difference The ratio of the two values ​​gives the rate of change of the resistance torque with respect to the rotational speed. ,Right now .

[0058] In some embodiments, at a rotational speed of At that time, the resistance torque It can be determined by the following formula (1).

[0059] (1)

[0060] in, This is the first actual torque value. The rate of change of the resistance torque with respect to the rotational speed. This is the first rotational speed value.

[0061] At a rotation speed of At that time, the resultant torque It can be determined by the following formula (2).

[0062] (2)

[0063] in, This is the actual step torque. The rate of change of the resistance torque with respect to the rotational speed. This is the first rotational speed value.

[0064] For any time t , and , They have the relationship shown in formula (3).

[0065] (3)

[0066] in, This is the first rotational speed value. The moment at which the predetermined step torque is applied. For the resultant torque, Let be the moment of inertia to be solved.

[0067] The process of determining the equivalent resultant torque and average angular acceleration of the range extender in the target stage based on the rate of change of the resistance torque with rotational speed, the actual step torque of the motor, the initial state data of the target stage, the final state data of the target stage, and the first state data may include the following operations: determining the average angular acceleration of the range extender in the target stage based on the initial state data and the final state data of the target stage; determining the second speed difference between the first stable state and the target stage based on the initial state data, the final state data of the target stage, and the first state data of the target stage; determining the equivalent resistance torque of the range extender in the target stage based on the rate of change of the resistance torque with rotational speed and the second speed difference; and obtaining the equivalent resultant torque of the range extender in the target stage based on the equivalent resistance torque and the actual step torque of the motor.

[0068] Based on the initial and final state data of the target phase, the process of determining the average angular acceleration of the range extender during the target phase is as follows: Based on the initial speed value... and termination speed value The difference is used to obtain the third speed difference of the range extender in the target stage. According to the third speed difference and the start time and termination time Time difference between The ratio of the two values ​​yields the average angular acceleration. .

[0069] In some embodiments, according to formula (3), the following can be obtained: , .

[0070] Substituting formula (2) into formula (3), and combining... You can get ,in, .

[0071] because stage It changes linearly with time, and we can obtain Thus, we can obtain .

[0072] Based on the initial speed value from the initial state data Termination speed value of termination status data and the first rotational speed value of the first state data The second speed difference between the range extender in the first steady state and the target stage can be determined. .

[0073] Based on the rate of change of resistance torque with rotational speed and the second speed difference Determine the equivalent drag torque of the range extender at the target stage. .

[0074] Based on the equivalent drag torque of the range extender at the target stage and the actual step torque of the motor The equivalent resultant torque of the range extender at the target stage can be obtained. , .

[0075] Based on the equivalent resultant torque With mean angular acceleration ( The ratio of ) can be obtained ,Right now .

[0076] Figure 3 A flowchart illustrating a method for determining the moment of inertia of a range extender according to another embodiment of the present disclosure is shown schematically.

[0077] like Figure 3 As shown, the method for determining the moment of inertia of the range extender in this embodiment may include operations S301 to S307.

[0078] When operating S301, maintain the engine fuel cut-off inside the range extender.

[0079] In operation S302, the range extender is driven to the first stable state by the motor, and the first speed value of the range extender and the first actual torque value of the motor are obtained when the first stable state is reached.

[0080] In operation S303, a predetermined step torque is applied to the motor.

[0081] In operation S304, the range extender is driven by the motor to the second stable state, and the second speed value and the second actual torque value of the motor in the second stable state are obtained.

[0082] In operation S305, the target stage is selected where the angular acceleration is stable and the rotational speed changes linearly with time between the first and second stable states.

[0083] In operation S306, calculate the resultant torque and mean angular acceleration of the target stage.

[0084] When operating S307, the moment of inertia is determined based on the resultant torque and the average angular acceleration.

[0085] This embodiment of the invention, while maintaining engine fuel cut-off, firstly drags the range extender to a stable first stable state via a motor, obtaining the first rotational speed value of the range extender and the first actual torque value of the motor in the first stable state; then, a predetermined step torque of a fixed value is applied to the motor, and under the combined action of the resistance torque and the motor torque, the range extender stabilizes to a second stable state, measuring the second rotational speed value of the range extender and the second actual torque value of the motor in the second stable state; assuming that the resistance torque changes linearly with the rotational speed during the transition from the first stable state to the second stable state, the rate of change of the resistance torque with the rotational speed is calculated, further obtaining the resistance torque and the resultant torque at different rotational speeds. The rotational speed at any given time can be calculated from the first rotational speed value and the resultant torque of the first stable state; the target stage of angular acceleration stabilization, i.e., linear change of rotational speed with time, during the transition from the first stable state to the second stable state is selected; the rotational inertia of the range extender is calculated from the average angular acceleration and the equivalent resultant torque of this target stage.

[0086] This disclosure utilizes the characteristic that the resistance torque is linearly related to the rotational speed within a certain range to provide a method for determining the moment of inertia of a motor through the step torque. This method involves little computation and can be applied in real time on actual vehicles. The results are accurate and consistent, and can be used to determine the equivalent moment of inertia and for self-learning in a specific speed range, thereby improving the modeling accuracy and control performance of the range extender.

[0087] The following describes a specific embodiment of the method for determining the moment of inertia of a range extender according to an embodiment of this disclosure.

[0088] Figure 4 The diagram illustrates the changes in torque, rotational speed, and angular velocity over time according to an embodiment of the present disclosure.

[0089] like Figure 4 As shown, the horizontal axis represents time, and the vertical axis, from top to bottom, represents torque, speed, and angular acceleration. With the engine maintaining a fuel cut-off, the range extender is first driven to a first stable state via the electric motor, and the first speed value of the range extender in this stable state is obtained. The first actual torque value of the motor .

[0090] exist A fixed step torque is applied to the motor at all times. And measure the actual step torque of the motor, such as Figure 4 , .

[0091] Using a motor with a predetermined step torque applied, the resultant torque of the resistance torque and the actual step torque of the motor is... Under the combined effect of these factors, the range extender is pulled from the first stable state to the second stable state, and the data in the second stable state is obtained. The second rotational speed value at time 1 The second actual torque value of the motor .

[0092] It is assumed that the resistance torque varies with the rotational speed during the transition from the first steady state to the second steady state. The linear change yields the rate of change of the resistance torque with respect to rotational speed. .

[0093] The target stage is selected between the first and second stable states, where angular acceleration is stable, i.e., the rotational speed changes linearly with time. For example... Figure 4 The curve of angular acceleration versus time in [the context] Before that moment, the rotational speed was stable, so the angular acceleration was 0. Time's up At time 1, the rotational speed transitions from a stable state to linear deceleration, but the angular acceleration is not linear, so it is not considered the target stage. From Time's up At time t, the rotational speed decreases linearly, while the angular acceleration remains a constant negative value. After a certain time, the rotational speed stabilizes and the angular acceleration becomes 0. Therefore, the selected target stage is... Time's up The stages between moments.

[0094] The start time of this target phase Termination time The initial rotational speed is Termination speed value ,but , .according to ,as well as The following process can be obtained:

[0095]

[0096] Therefore, the moment of inertia of the range extender in this embodiment is .

[0097] Based on the above-described method for determining the moment of inertia of a range extender, this disclosure also provides an apparatus for determining the moment of inertia of a range extender. The following will be combined with... Figure 5 The device is described in detail.

[0098] Figure 5 A schematic block diagram of a device for determining the moment of inertia of a range extender according to an embodiment of the present disclosure is shown.

[0099] like Figure 5As shown, the device 500 for determining the rotational inertia of the range extender in this embodiment includes a first acquisition module 510, a second acquisition module 520, and a first determination module 530.

[0100] The first acquisition module 510 is used to drag the range extender to a first stable state by a motor while maintaining the engine fuel cut-off inside the range extender, and to acquire the first state data of the first stable state.

[0101] The second acquisition module 520 is used to continue to drag the range extender from the first stable state to the second stable state using a motor with a predetermined step torque applied, and to acquire the second state data of the second stable state, as well as the actual step torque generated by the motor under the predetermined step torque, wherein the first speed difference between the second stable state and the first stable state is less than a predetermined value.

[0102] The first determining module 530 is used to select a target stage during the period from the first stable state to the second stable state, and determine the rotational inertia of the range extender based on the start state data, end state data, first state data, second state data and actual step torque of the target stage.

[0103] In some embodiments, the first determining module 530 may include a first determining unit, a second determining unit, and a third determining unit.

[0104] The first determining unit is used to determine the rate of change of the range extender's resistance torque with respect to the rotational speed based on the first state data and the second state data.

[0105] The second determining unit is used to determine the equivalent resultant torque and average angular acceleration of the range extender in the target stage based on the rate of change of the resistance torque with the rotational speed, the actual step torque of the motor, the initial state data of the target stage, the final state data of the target stage, and the first state data.

[0106] The third determining unit is used to obtain the moment of inertia of the range extender based on the ratio of the equivalent resultant torque to the average angular acceleration.

[0107] In some embodiments, the first determining unit may include a first determining subunit and a second determining subunit.

[0108] The first determining subunit is used to obtain the actual torque deviation of the motor based on the first actual torque value and the second actual torque value.

[0109] The second determining subunit is used to obtain the rate of change of the resistance torque with the rotational speed based on the ratio of the actual torque deviation to the speed difference between the second rotational speed value and the first rotational speed value.

[0110] In some embodiments, the apparatus 500 for determining the rotational inertia of the range extender may further include a third acquisition module, a filtering module, and a second determination module.

[0111] The third acquisition module is used to acquire the first original speed signal and the first original torque signal under the first stable state, and to acquire the second original speed signal and the second original torque signal under the second stable state.

[0112] The filtering module is used to filter the first original speed signal, the first original torque signal, the second original speed signal, and the second original torque signal respectively to obtain the first target speed signal, the first target torque signal, the second target speed signal, and the second target torque signal. The speed fluctuation value of the first target speed signal and the second target speed signal, as well as the torque fluctuation value of the first target torque signal and the second target torque signal, are less than a predetermined threshold within a first predetermined time period.

[0113] The second determining module is used to obtain the first speed value, the first actual torque value, the second speed value, and the second actual torque value based on the characteristic values ​​of the first target speed signal, the first target torque signal, the second target speed signal, and the second target torque signal, respectively.

[0114] In some embodiments, the second determining unit may include a third determining subunit, a fourth determining subunit, a fifth determining subunit, and a sixth determining subunit.

[0115] The third determining subunit is used to determine the average angular acceleration of the range extender in the target phase based on the initial state data and the final state data of the target phase.

[0116] The fourth determining subunit is used to determine the second speed difference between the range extender and the target stage based on the start state data of the target stage, the end state data of the target stage, and the first state data.

[0117] The fifth determining subunit is used to determine the equivalent resistance torque of the range extender in the target stage based on the rate of change of the resistance torque with the rotational speed and the second speed difference.

[0118] The sixth determination sub-unit is used to obtain the equivalent resultant torque of the range extender in the target stage based on the equivalent resistance torque and the actual step torque of the motor.

[0119] In some embodiments, the third determining subunit is further configured to obtain the third speed difference of the range extender in the target stage based on the difference between the starting speed value and the ending speed value; and to obtain the average angular acceleration based on the ratio of the third speed difference to the time difference between the starting time and the ending time.

[0120] According to embodiments of this disclosure, any plurality of modules among the first acquisition module 510, the second acquisition module 520, and the first determination module 530 can be combined into one module, or any one of these modules can be split into multiple modules. Alternatively, at least part of the functionality of one or more of these modules can be combined with at least part of the functionality of other modules and implemented in one module. According to embodiments of this disclosure, at least one of the first acquisition module 510, the second acquisition module 520, and the first determination module 530 can be at least partially implemented as hardware circuitry, such as a field-programmable gate array (FPGA), a programmable logic array (PLA), a system-on-a-chip, a system-on-a-substrate, a system-on-package, an application-specific integrated circuit (ASIC), or implemented by any other reasonable means of integrating or packaging circuitry, or implemented in any one of software, hardware, and firmware methods, or in a suitable combination of any of these. Alternatively, at least one of the first acquisition module 510, the second acquisition module 520, and the first determination module 530 can be at least partially implemented as a computer program module, which, when run, can perform corresponding functions.

[0121] Figure 6 A block diagram schematically illustrates an electronic device suitable for implementing a method for determining the moment of inertia of a range extender, according to an embodiment of the present disclosure.

[0122] like Figure 6 As shown, an electronic device 600 according to an embodiment of this disclosure includes a processor 601, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 602 or a program loaded from a storage portion 608 into a random access memory (RAM) 603. The processor 601 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 601 may also include onboard memory for caching purposes. The processor 601 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of this disclosure.

[0123] RAM 603 stores various programs and data required for the operation of electronic device 600. Processor 601, ROM 602, and RAM 603 are interconnected via bus 604. Processor 601 performs various operations of the method flow according to embodiments of the present disclosure by executing programs in ROM 602 and / or RAM 603. It should be noted that the programs may also be stored in one or more memories other than ROM 602 and RAM 603. Processor 601 may also perform various operations of the method flow according to embodiments of the present disclosure by executing programs stored in said one or more memories.

[0124] According to embodiments of this disclosure, the electronic device 600 may further include an input / output (I / O) interface 605, which is also connected to a bus 604. The electronic device 600 may also include one or more of the following components connected to the input / output (I / O) interface 605: an input section 606 including a keyboard, mouse, etc.; an output section 607 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 608 including a hard disk, etc.; and a communication section 609 including a network interface card such as a LAN card, modem, etc. The communication section 609 performs communication processing via a network such as the Internet. A drive 610 is also connected to the input / output (I / O) interface 605 as needed. A removable medium 611, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 610 as needed so that computer programs read from it can be installed into the storage section 608 as needed.

[0125] This disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The computer-readable storage medium carries one or more programs that, when executed, implement the method according to the embodiments of this disclosure.

[0126] According to embodiments of this disclosure, the computer-readable storage medium may be a non-volatile computer-readable storage medium, such as including, but not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this disclosure, the computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. For example, according to embodiments of this disclosure, the computer-readable storage medium may include ROM 602 and / or RAM 603 and / or one or more memories other than ROM 602 and RAM 603 described above.

[0127] Embodiments of this disclosure also include a computer program product comprising a computer program containing program code for performing the methods shown in the flowchart. When the computer program product is run on a computer system, the program code is used to cause the computer system to implement the methods provided in the embodiments of this disclosure.

[0128] When the computer program is executed by the processor 601, it performs the functions defined in the system / apparatus of this disclosure embodiments. According to embodiments of this disclosure, the systems, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0129] In one embodiment, the computer program may rely on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may also be transmitted and distributed in the form of signals over a network medium, and downloaded and installed via the communication section 609, and / or installed from the removable medium 611. The program code contained in the computer program can be transmitted using any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination thereof.

[0130] In such an embodiment, the computer program can be downloaded and installed from a network via the communication section 609, and / or installed from the removable medium 611. When the computer program is executed by the processor 601, it performs the functions defined in the system of this disclosure embodiment. According to embodiments of this disclosure, the systems, devices, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0131] According to embodiments of this disclosure, program code for executing the computer programs provided in embodiments of this disclosure can be written in any combination of one or more programming languages. Specifically, these computational programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, languages ​​such as Java, C++, Python, "C", or similar programming languages. The program code can execute entirely on a user's computing device, partially on a user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0132] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0133] Those skilled in the art will understand that the features described in the various embodiments of this disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments of this disclosure can be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0134] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A method for determining the moment of inertia of a range extender, characterized in that, The method includes: While maintaining the engine fuel cut-off inside the range extender, the range extender is dragged to the first stable state by the electric motor, and the first state data of the first stable state is acquired. The range extender is continued to be dragged from the first stable state to the second stable state by a motor with a predetermined step torque applied, and the second state data of the second stable state and the actual step torque generated by the motor under the predetermined step torque are obtained, wherein the first speed difference between the second stable state and the first stable state is less than a predetermined value. A target phase is selected during the period from the first stable state to the second stable state, and the moment of inertia of the range extender is determined based on the start state data, end state data, first state data, second state data, and the actual step torque of the target phase.

2. The method according to claim 1, characterized in that, The step of determining the moment of inertia of the range extender based on the initial state data, the final state data, the first state data, the second state data, and the actual step torque of the target stage includes: Based on the first state data and the second state data, determine the rate of change of the range extender's resistance torque with respect to rotational speed; Based on the rate of change of the resistance torque with rotational speed, the actual step torque of the motor, the initial state data of the target stage, the final state data of the target stage, and the first state data, the equivalent resultant torque and average angular acceleration of the range extender in the target stage are determined. The moment of inertia of the range extender is obtained based on the ratio of the equivalent resultant torque to the average angular acceleration.

3. The method according to claim 2, characterized in that, The first state data includes the first speed value of the range extender and the first actual torque value of the motor; the second state data includes the second speed value of the range extender and the second actual torque value of the motor. Determining the rate of change of the range extender's resistance torque with respect to rotational speed based on the first state data and the second state data includes: The actual torque deviation of the motor is obtained based on the first actual torque value and the second actual torque value; The rate of change of the resistance torque with respect to the rotational speed is obtained based on the ratio of the actual torque deviation to the speed difference between the second rotational speed value and the first rotational speed value.

4. The method according to claim 3, characterized in that, The first state data and the second state data are obtained in the following ways: The first original speed signal and the first original torque signal under the first stable state are obtained respectively, and the second original speed signal and the second original torque signal under the second stable state are obtained respectively; The first original speed signal, the first original torque signal, the second original speed signal, and the second original torque signal are filtered respectively to obtain the first target speed signal, the first target torque signal, the second target speed signal, and the second target torque signal. The speed fluctuation value of the first target speed signal, the speed fluctuation value of the second target speed signal, the torque fluctuation value of the first target torque signal, and the torque fluctuation value of the second target torque signal are less than a predetermined threshold within a first predetermined time period. Based on the characteristic values ​​of the first target speed signal, the first target torque signal wave, the second target speed signal, and the second target torque signal, the first speed value, the first actual torque value, the second speed value, and the second actual torque value are obtained respectively.

5. The method according to claim 2, characterized in that, The step of determining the equivalent resultant torque and mean angular acceleration of the range extender in the target stage based on the rate of change of the resistance torque with rotational speed, the actual step torque of the motor, the initial state data of the target stage, the final state data of the target stage, and the first state data includes: Based on the initial state data and the final state data of the target phase, the average angular acceleration of the range extender during the target phase is determined. Based on the start state data of the target stage, the end state data of the target stage, and the first state data, determine the second speed difference of the range extender between the first stable state and the target stage; The equivalent resistance torque of the range extender at the target stage is determined based on the rate of change of the resistance torque with the rotational speed and the second rotational speed difference. Based on the equivalent resistance torque and the actual step torque of the motor, the equivalent resultant torque of the range extender at the target stage is obtained.

6. The method according to claim 5, characterized in that, The initial state data includes the initial time and the initial rotational speed; the final state data includes the final time and the final rotational speed. Determining the average angular acceleration of the range extender during the target phase based on the initial state data and the final state data of the target phase includes: The third speed difference of the range extender at the target stage is obtained based on the difference between the starting speed value and the ending speed value. The average angular acceleration is obtained by the ratio of the third rotational speed difference to the time difference between the start time and the end time.

7. A device for determining the moment of inertia of a range extender, characterized in that, The device includes: The first acquisition module is used to drag the range extender to a first stable state by a motor while maintaining the engine fuel cut-off inside the range extender, and to acquire the first state data of the first stable state. The second acquisition module is used to continue to drag the range extender from the first stable state to the second stable state using a motor with a predetermined step torque applied, and to acquire the second state data of the second stable state, as well as the actual step torque generated by the motor under the predetermined step torque, wherein the first speed difference between the second stable state and the first stable state is less than a predetermined value. The first determining module is used to select a target stage during the period from the first stable state to the second stable state, and determine the rotational inertia of the range extender based on the start state data, end state data, first state data, second state data and the actual step torque of the target stage.

8. An electronic device, comprising: One or more processors; Memory, used to store one or more computer programs. The characteristic feature is that the one or more processors execute the one or more computer programs to implement the steps of the method according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by a processor, they implement the steps of the method according to any one of claims 1 to 7.

10. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed by a processor, they implement the steps of the method according to any one of claims 1 to 7.

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