Range extender NVH optimization method, range extender and electric vehicle

Abstract

The invention discloses a range extender NVH (Noise Vibration and Harshness) optimization method, a range extender and an electric vehicle, and aims to improve the power generation load power of a range extender controller and reduce the power generation load power of the range extender controller in two stages of an intake stroke and a compression stroke in an adjustment period of the range extender when set conditions are met. Hardware does not need to be changed, NVH optimization of the whole vehicle is achieved by dynamically adjusting the generated power according to the rotating speed difference of the four strokes, and rotating speed jump impact is effectively restrained.

Description

Technical Field

[0001] This invention relates to the field of range extender technology, specifically to a range extender NVH optimization method, a range extender, and a tram. Background Technology

[0002] Range-extended electric vehicles (REEVs) offer a solution that leverages the performance of pure electric vehicles while mitigating range anxiety to some extent. However, current research and development largely focuses on improving the thermal efficiency and reducing the size of range extenders. This has resulted in generally unsatisfactory NVH (Noise, Vibration, and Harshness) performance in both four-wheeled and two-wheeled REEVs. Noise and vibration are significant factors affecting vehicle performance and comfort. This is especially true for REEVs, as they cannot utilize methods like range extender mounting and acoustic enclosures found in automobiles. Their NVH performance relies almost entirely on the range extender itself, making it difficult to achieve effective noise reduction.

[0003] Electric motorcycle range extenders typically use a single-cylinder design. Lacking the crankshaft phase balancing mechanism inherent in multi-cylinder engines (such as the phase difference in the power strokes of a four-cylinder car engine to cancel each other out), their second-order vibration and noise levels are significantly higher than multi-cylinder models. The significant differences in engine speed across the four strokes of a single-cylinder internal combustion engine lead to noticeable vibrations throughout the vehicle. During the power stroke, the engine speed experiences a burst of speed increase, rising significantly. The exhaust and intake strokes show a certain degree of speed reduction. The compression stroke shows a significant decrease in speed. Based on a comparison of the relationship between the vehicle's ignition signal, Hall effect signal, and generator current, at 3000 rpm, the power stroke speed is generally 18% faster than the compression stroke speed in the four-stroke cycle. This also contributes to the unsatisfactory vibration and noise performance of the range extender.

[0004] Therefore, as competition in the four-wheeled and two-wheeled markets intensifies, increasingly higher demands are being placed on the NVH performance of range-extended vehicles. The market needs a method to directly improve the NVH of range extenders by optimizing the control strategy. Especially for range-extended two-wheeled vehicles, optimizing the control strategy to improve NVH is the most practical and feasible strategy.

[0005] In the existing technology:

[0006] Patent application CN202210513841.7 collects and tabulates data on the range extender's speed, torque, fuel consumption, vibration, and noise. Through CAE analysis and the use of neural networks to construct nonlinear shutdown parameters related to fuel consumption, key rotational dynamic stress cycles, range extender vibration, cab sound pressure level, and speed, a MAP (Motion Map) of range extender fuel consumption, vibration, and cab sound pressure level is generated. Finally, using the MAP, actual sound pressure levels, and vehicle speed, an adaptive particle swarm optimization algorithm is employed to determine the optimal NVH (Noise, Vibration, and Harshness) operating range for the range extender under different operating conditions.

[0007] Patent application CN202411202716.X describes a power limiting strategy based on vehicle speed, throttle opening, and battery SOC. This strategy collects necessary parameters in real-time during vehicle operation and limits power output, thereby improving overall vehicle NVH (noise, vibration, and harshness).

[0008] The patent application CN202410034143.8 uses simulation to confirm the speed range in which the range extender will resonate, and avoids the speed range in which resonance occurs during vehicle operation. This improves the overall NVH performance of the vehicle.

[0009] The above three solutions essentially improve the NVH of the range extender by changing its operating range. While these methods are effective, they still have the following drawbacks:

[0010] 1. When the vehicle is in power-following mode, forcibly avoiding certain speed points may cause drastic changes in vehicle speed.

[0011] 2. Some small range extenders (such as those made from single-cylinder internal combustion engines) have limited hardware, resulting in poor NVH (Noise, Vibration, and Harshness) at most operating points. Therefore, it's impossible to optimize the overall vehicle NVH by avoiding certain operating points. Summary of the Invention

[0012] The purpose of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a range extender NVH optimization method, range extender and tram, which can achieve range extender NVH optimization without adding any new hardware.

[0013] This invention is achieved through the following technical solution:

[0014] A method for optimizing the NVH (Noise, Vibration, and Harshness) of a range extender, comprising the following steps

[0015] When the set conditions are met, within one adjustment cycle of the range extender, the power generation load of the range extender controller is increased during the working stroke and exhaust stroke, and the power generation load of the range extender controller is decreased during the intake stroke and compression stroke.

[0016] As a further improvement of the present invention, when the range extender receives the fuel injection and ignition command from the internal combustion engine, it marks the beginning of an adjustment cycle, and when the range extender receives the next fuel injection and ignition command from the internal combustion engine, it marks the end of an adjustment cycle.

[0017] As a further improvement of the present invention, the step of increasing the power generation load of the range extender controller in the two stages of the working stroke and the exhaust stroke includes:

[0018] The process consists of two phases: the power stroke and the exhaust stroke. Based on the current speed of the internal combustion engine and the current power of the generator, the power value of the range extender is obtained by looking up a table. The range extender then increases the generator torque based on the power value.

[0019] As a further improvement of the present invention, the step of reducing the power generation load of the range extender controller during the intake and compression strokes includes:

[0020] The range extender operates in two phases: the intake stroke and the compression stroke. Based on the current speed of the internal combustion engine and the current power of the generator, the power value of the range extender is obtained by looking up a table. The range extender then reduces the generator torque based on the power value.

[0021] As a further improvement of the present invention, if the control response time of the range extender controller is less than or equal to the set time value, the range extender controller increases or decreases the power generation load.

[0022] As a further improvement of the present invention, the set time value t Tim Determined by the following formula:

[0023]

[0024] in, For each cycle time, t latency This represents the system delay time.

[0025] As a further improvement of the present invention, during the process of increasing or decreasing the power generation load, the power of the range extender controller is within a set safety threshold.

[0026] The present invention also provides a range extender for implementing the above-mentioned range extender NVH optimization method, comprising: an internal combustion engine, a range extender controller, and a fuel injection electronic control unit;

[0027] The internal combustion engine is connected to the range extender controller via a generator encoder line and a three-phase power bus, and the internal combustion engine is connected to the fuel injection electronic control unit via an internal combustion engine sensor line.

[0028] The range extender controller is connected to the internal combustion engine, the fuel injection electronic control unit, and other vehicle controllers via a CAN bus.

[0029] The present invention also provides an electric vehicle, including the range extender described above.

[0030] Compared to existing technologies, this invention offers the following advantages: It requires no hardware modifications and optimizes vehicle NVH (Noise, Vibration, and Harshness) by dynamically adjusting power generation to address the speed differences across the four strokes, effectively suppressing speed jump shocks. Unlike existing technologies that quickly bypass unfavorable speed ranges, this invention avoids NVH deterioration by rapidly navigating unfavorable speed ranges (such as resonance points), instead optimizing the ignition cycle of each internal combustion engine. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 The relationship between ignition signal and speed change, and the corresponding power generation change curve;

[0033] Figure 2 This is a schematic diagram of the range extender described in Example 2. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1

[0036] This embodiment provides a method for optimizing the NVH (Noise, Vibration, and Harshness) of a range extender, including the following steps:

[0037] When the set conditions are met, within one adjustment cycle of the range extender, the power generation load of the range extender controller is increased during the working stroke and exhaust stroke, and the power generation load of the range extender controller is decreased during the intake stroke and compression stroke.

[0038] The current stroke of the range extender can be determined by the crankshaft phase.

[0039] The settings can be adjusted based on actual conditions. For example, the settings could be: vehicle speed less than or equal to 25 km / h and range extender power greater than or equal to 3 kW. When the vehicle speed exceeds 60 km / h, vibration and noise primarily originate from road vibrations and wind noise. In this case, the benefits of range extender NVH optimization are minimal. When the vehicle speed is low and the range extender is operating normally, more vibration and noise originate from the range extender itself, making range extender NVH optimization more effective. The specific speed range above which range extender NVH optimization is ineffective, and the required generator load power of the range extender for NVH optimization, are primarily determined by the overall vehicle characteristics and range extender matching. Parameter optimization requires bench testing and real-vehicle matching, with the matching principle following... The critical curve is the NVH effect of the range extender that is equivalent to the NVH effect of the generator power generated at the current driving speed under the same operating condition.

[0040] In the above formula, This indicates the cumulative impact of speed changes on the overall vehicle's NVH (noise, vibration, and harshness) within a certain speed range. This indicates the cumulative impact of power generation variations on NVH within a certain power generation range. At certain vehicle speeds, if the NVH caused by road noise and wind noise is already significant, then the proportion of NVH from the power generation end becomes smaller, and the benefit of adjusting it is not high. Therefore, the critical line is defined as when the effects of both are equal.

[0041] When the range extender controller receives the fuel injection and ignition command from the internal combustion engine, it marks the beginning of an adjustment cycle; when the range extender controller receives the next fuel injection and ignition command from the internal combustion engine, it marks the end of an adjustment cycle. The crankshaft range in the cycle is (θ∈[0-actual ignition angle, 720°-actual ignition angle]).

[0042] The system consists of two phases: the power stroke and the exhaust stroke. Based on the current speed of the internal combustion engine and the current power of the generator, the power value of the range extender is obtained by looking up a table. The range extender increases the generator torque based on the power value to suppress the burst speed generated in these two strokes.

[0043]

[0044] The intake and compression strokes are divided into two stages. Based on the current speed of the internal combustion engine and the current power of the generator, the power value of the range extender is obtained by looking up a table. The range extender reduces the generator torque based on the power value, which helps to smooth the rotation of these two strokes that rely on inertial rotation.

[0045] When the range extender controller controls the internal combustion engine to generate electricity at the target speed and power, the fuel injection electronic control unit sends injection ignition commands to the internal combustion engine, which are also synchronously transmitted to the range extender controller via hardwired transmission. Upon receiving the hardwired injection ignition signal, the range extender controller fine-tunes the power generation load corresponding to the four strokes currently in progress. The range extender controller determines the current speed by receiving the A, B, and Z signals from the magnetic encoder on the generator. By combining the injection ignition signal and the current speed, the range extender controller obtains the compensation torque for the current state through a lookup table, controlling the dynamic changes in the power generation load. During the interval from the start of the power stroke to the end of the exhaust stroke, the power generation load is increased based on the lookup table data; during the interval from the start of the intake stroke to the end of the compression stroke, the power generation load is decreased based on the lookup table data. This achieves periodic dynamic adjustment of the power generation load, thereby reducing speed fluctuations in a single-cylinder range extender and optimizing its vibration and noise levels.

[0046] Because the internal combustion engine operates at high speeds, the control response time available for the range extender controller is limited. Therefore, the controller's response speed is subject to certain requirements. If the range extender controller's control response time is less than or equal to a set time value, the controller will either increase or decrease the generator load power. The set time value is t. Tim Determined by the following formula:

[0047]

[0048] in, For each cycle time, t latency This represents the system delay time.

[0049] During the process of dynamically adjusting the power generation load, the actual power P of the range extender controller... ISG It must always be kept within the safety boundary, i.e., P min ≤P ISG ≤P max If the actual power P of the range extender controller ISG Excessive or insufficient power output may lead to severe distortion of the power generation waveform. The total power generation resulting from the increase or decrease in power generation load power remains consistent with the power generation without employing the range extender NVH optimization method described above.

[0050]

[0051] This embodiment achieves active suppression of four-stroke speed fluctuations in a single-cylinder range extender through real-time closed-loop control of "ignition signal → crankshaft phase → power generation". Employing a dynamic power generation algorithm, it dynamically increases load during the power / exhaust strokes and dynamically decreases load during the intake / compression strokes, significantly reducing speed fluctuations in the single-cylinder range extender and optimizing NVH (noise, vibration, and harshness) without adding any new hardware.

[0052] Example 2

[0053] This embodiment 2 provides a range extender, characterized in that it is used to implement the range extender NVH optimization method described in embodiment 1, such as... Figure 2 As shown, it includes: an internal combustion engine, a range extender controller, and a fuel injection electronic control unit; the internal combustion engine is connected to the range extender controller via a generator encoder line and a three-phase power bus, and the internal combustion engine is connected to the fuel injection electronic control unit via an internal combustion engine sensor line; the range extender controller is connected to the internal combustion engine, the fuel injection electronic control unit, and other vehicle controllers via a CAN bus.

[0054] For other technical details of this embodiment, please refer to the prior art, which will not be repeated here.

[0055] Example 3

[0056] This embodiment provides an electric vehicle, including the range extender in Embodiment 2. For the specific implementation process of this embodiment, please refer to Embodiments 1 and 2, which will not be repeated here.

[0057] As can be seen from the above embodiments, the present invention has the following technical effects:

[0058] 1. Significant cost advantage, requiring no hardware modifications. This method can be deployed using only the original magnetic encoder / Hall effect sensor, fuel injection electronic control unit, and range extender controller of the range extender, without the need for any additional controllers or mechanical structures.

[0059] 2. Strong adaptability to operating conditions and hardware. The system optimizes vehicle NVH by dynamically adjusting the generator power to address the speed differences across the four strokes, effectively suppressing shocks from speed jumps. It is applicable to any speed and power range based on the range extender's characteristics. While this method is most effective on small single-cylinder range extenders, it can still be deployed to other multi-cylinder range extenders.

[0060] 3. Real-time dynamic compensation, without limiting the speed range or avoiding specific speed ranges. Existing related patents essentially optimize vehicle NVH by avoiding specific speed ranges. This method optimizes NVH from the perspective of adjusting speed fluctuations.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for optimizing the NVH (Noise, Vibration, and Harshness) of a range extender, characterized in that, Including the following steps: When the set conditions are met, within one adjustment cycle of the range extender, the power generation load of the range extender controller is increased during the working stroke and exhaust stroke, and the power generation load of the range extender controller is decreased during the intake stroke and compression stroke.

2. The NVH optimization method for range extenders according to claim 1, characterized in that, When the range extender receives the fuel injection and ignition command from the internal combustion engine, it marks the beginning of an adjustment cycle; when the range extender receives the next fuel injection and ignition command from the internal combustion engine, it marks the end of an adjustment cycle.

3. The range extender NVH optimization method according to claim 1, characterized in that, The steps for increasing the power generation load of the range extender controller during the two phases of the power stroke and exhaust stroke include: The process consists of two phases: the power stroke and the exhaust stroke. Based on the current speed of the internal combustion engine and the current power of the generator, the power value of the range extender is obtained by looking up a table. The range extender then increases the generator torque based on the power value.

4. The range extender NVH optimization method according to claim 3, characterized in that, The steps for reducing the power generation load of the range extender controller during the intake and compression strokes include: The range extender operates in two phases: the intake stroke and the compression stroke. Based on the current speed of the internal combustion engine and the current power of the generator, the power value of the range extender is obtained by looking up a table. The range extender then reduces the generator torque based on the power value.

5. The NVH optimization method for range extenders according to any one of claims 1 to 4, characterized in that, If the control response time of the range extender controller is less than or equal to the set time value, the range extender controller will increase or decrease the power generation load.

6. The range extender NVH optimization method according to claim 5, characterized in that, The set time value t Tim Determined by the following formula: in, For each cycle time, t latency This represents the system delay time.

7. The NVH optimization method for range extenders according to any one of claims 1 to 4, characterized in that, During the process of increasing or decreasing the power generation load, the power of the range extender controller remains within the set safety threshold.

8. A range extender, characterized in that, The method for implementing the range extender NVH optimization method as described in any one of claims 1 to 7 is characterized in that it comprises: an internal combustion engine, a range extender controller, and a fuel injection electronic control unit; The internal combustion engine is connected to the range extender controller via a generator encoder line and a three-phase power bus, and the internal combustion engine is connected to the fuel injection electronic control unit via an internal combustion engine sensor line. The range extender controller is connected to the internal combustion engine, the fuel injection electronic control unit, and other vehicle controllers via a CAN bus.

9. An electric vehicle, characterized in that, Includes the range extender as described in claim 9.

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