Jitter suppression method for engine

Abstract

The invention provides a jitter suppression method for an engine. The jitter suppression method comprises the following steps: constructing a delay function and a pulse torque compensation function; a corresponding pulse signal is generated while an ignition signal is generated in each four-stroke cycle; the motor controller starts a monitoring program according to the pulse signal, and the monitoring program generates a pulse compensation instruction according to the delay function and the pulse torque compensation function; and in each four-stroke cycle, the motor controller controls a motor to execute the torque adjustment value corresponding to the pulse compensation instruction according to the pulse compensation instruction and the whole vehicle instruction. According to the method, the jitter time of the engine in each four-stroke period is determined by constructing the delay function, and the torque compensation amplitude of the jitter of the engine is determined by constructing the pulse torque compensation function, so that the jitter of the engine in each four-stroke period can be inhibited and adjusted in time.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle control, and in particular relates to a method for suppressing engine vibration. Background Art

[0002] With the development of science and technology, the extended-range hybrid system composed of an internal combustion engine and an electric motor is increasingly widely used in the fields of sea, land and air transportation. In this hybrid system, the internal combustion engine plays an important role, and its working process includes multiple periodic four-stroke cycles.

[0003] Take a common four-cylinder engine as an example. In two mechanical rotation cycles, there will be four compression strokes and four power strokes. These compression strokes and power strokes will produce jitter problems during operation. Due to the working characteristics of each compression stroke and power stroke, they will cause pulsation in the engine output torque. This pulsation is periodic and persists as the engine continues to run.

[0004] When the output torque of the engine pulsates, it will have an adverse effect on the entire extended-range hybrid system. This impact is mainly reflected in two aspects: on the one hand, the continuous jitter seriously affects the ride comfort of the vehicle. Passengers can clearly feel the discomfort caused by the jitter, which greatly reduces the travel experience. On the other hand, this jitter has an unignorable negative effect on the mechanical reliability and service life of the system. Long-term jitter will cause additional stress to the various components inside the system, accelerate the wear of the components, and increase the probability of failure, thereby shortening the service life of the entire system, increasing maintenance costs and the frequency of replacement of parts, which poses a challenge to the stability and economy of the extended-range hybrid system in large-scale applications. Summary of the invention

[0005] In order to solve the problem described in the background art that the output torque of the engine pulsates and causes adverse effects on the entire extended-range hybrid system, the present invention proposes the following technical solutions:

[0006] A method for suppressing engine vibration comprises the following steps:

[0007] Construct delay function and pulse torque compensation function;

[0008] In each four-stroke cycle, an ignition signal is generated and a corresponding pulse signal is generated at the same time;

[0009] The motor controller starts a monitoring program according to the pulse signal, and the monitoring program generates a pulse compensation instruction according to the delay function and the pulse torque compensation function;

[0010] In each of the four-stroke cycles, the motor controller controls the motor to execute the torque adjustment value corresponding to the pulse compensation instruction according to the pulse compensation instruction and the vehicle instruction.

[0011] Wherein, the monitoring program includes the following steps: determining whether the current operating condition of the engine meets the compensation condition;

[0012] Calculate and generate a delay time T according to the delay function;

[0013] Calculate the torque adjustment value according to the pulse torque compensation function and generate the corresponding pulse compensation instruction;

[0014] performing amplitude limiting processing on the pulse compensation instruction;

[0015] The motor controller controls the motor to execute the torque adjustment value after the delay time T.

[0016] Furthermore, the delay function includes a mapping relationship between the ignition signal and the engine jitter time difference under different motor speeds; the pulse torque compensation function iteratively optimizes the torque adjustment value by establishing an initial value, thereby establishing a mapping relationship based on the delay function; wherein each speed of the motor corresponds to a torque adjustment value.

[0017] Furthermore, the compensation conditions include: the rotation speed of the motor is less than 50% of the peak rotation speed and greater than the idle rotation speed, and the motor controller fails.

[0018] Furthermore, when the running state of the engine satisfies one of the compensation conditions, the monitoring program generates the compensation instruction; otherwise, the motor controller controls the motor execution torque only according to the vehicle instruction.

[0019] Furthermore, in the four-stroke cycle, when the motor controller does not receive the pulse signal, the motor controller controls the motor to execute the torque adjustment value only according to the vehicle instruction.

[0020] Furthermore, before controlling the motor to execute the torque adjustment value, the motor controller needs to limit the torque adjustment value.

[0021] Beneficial effect: The present invention constructs a delay function to determine the time when the engine jitters in each four-stroke cycle, and constructs a pulse torque compensation function to determine the torque compensation amplitude of the engine jitter, thereby ensuring that the engine can be promptly suppressed and adjusted when it jitters in each four-stroke cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1is a flow chart of a method for suppressing engine vibration according to an embodiment of the present invention;

[0023] Figure 2 The figure is a signal transmission flow chart of a method for suppressing engine vibration according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present application clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] It should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this patent.

[0026] Figure 1 The figure is a flow chart of a method for suppressing engine vibration according to an embodiment of the present invention.

[0027] Reference Figure 1 According to an embodiment of the present invention, a method for suppressing engine vibration comprises the following steps:

[0028] S000. Construct a delay function and a pulse torque compensation function.

[0029] Specifically, in this step, both the delay function and the pulse torque compensation function need to be constructed in advance so that they can be called in the subsequent use process. Among them, the delay function and the pulse torque compensation function are both piecewise functions, and their respective mapping relationships need to be calculated in advance based on the time interval from the ignition signal to the engine jitter in the same four-stroke cycle at each motor speed, so as to complete the one-to-one correspondence between the engine speed and the jitter delay.

[0030] The construction of the pulse torque compensation function needs to be based on the delay function. During each debugging process, the motor torque is adjusted according to the time corresponding to the delay function, and repeated debugging and optimization are performed after setting the initial value. During the debugging process, it is necessary to first test the engine vibration degree at a certain motor speed, and then modify the initial value one by one and test the degree of engine vibration repair after superimposed compensation at the same motor speed.

[0031] After multiple tests, the initial value with the best engine vibration repair degree is selected from the test results as the pulse torque compensation amplitude at the motor speed. After determining the pulse torque compensation amplitude at a certain motor speed, the next motor speed is tested in turn, thereby completing the mapping relationship between each motor speed and the pulse torque compensation amplitude.

[0032] S010. Generate an ignition signal and a corresponding pulse signal at the same time in each four-stroke cycle.

[0033] Specifically, each four-stroke cycle includes the following processes: intake, compression, power, and exhaust, a total of four different processes. During the operation of the engine, each four-stroke cycle is carried out in sequence. Among them, the engine controller generates an ignition signal during the power stage, and generates a corresponding pulse signal at the same time as the ignition signal is issued and sends it to the motor controller. The motor controller needs to control the motor to execute the corresponding torque during each four-stroke cycle to maintain the operation of each four-stroke cycle.

[0034] Figure 2 The figure is a signal transmission flow chart of a method for suppressing engine vibration according to an embodiment of the present invention.

[0035] S020. The motor controller starts a monitoring program according to the pulse signal, and the monitoring program generates a pulse compensation instruction according to the delay function and the pulse torque compensation function.

[0036] Reference Figure 2 Specifically, the motor controller starts the monitoring program after receiving the pulse signal. Before generating the compensation torque amplitude, the monitoring program needs to determine whether the current operating condition of the engine meets the compensation conditions. Among them, the compensation conditions are: the current speed of the motor is lower than 50% of the peak speed and higher than the idle speed, and the motor controller fails. If one of the above conditions is met, the monitoring program generates a compensation instruction and a delay time T according to the pulse torque compensation function and the delay function respectively.

[0037] Specifically, after generating the pulse torque compensation instruction and the delay time T, the timer needs to determine whether the running time has passed the delay time T. The delay time T is the interval between the issuance of the pulse signal and the issuance of the pulse compensation instruction. Before the delay time T is reached, the motor controller only controls the motor to execute the corresponding torque in the vehicle instruction according to the whole machine instruction. When the delay time T is reached, the motor controller superimposes the pulse compensation instruction and the vehicle instruction, thereby controlling the motor to execute the torque adjustment value. At this time, the torque adjustment amplitude of the motor is formed by the superposition of the torque value in the vehicle instruction and the torque adjustment value in the pulse compensation instruction.

[0038] Preferably, in order to prevent the motor from executing a torque adjustment value that exceeds its own design level, in this embodiment, the pulse compensation instruction needs to be limited after being generated, so as to adjust the calculated torque adjustment value so as not to exceed the maximum adjustment range allowed by the motor design. Furthermore, in order to prevent the torque adjustment value formed by the compensation torque amplitude in the compensation instruction from exceeding the maximum adjustment range of the motor design after superimposing the torque value in the vehicle instruction, in this embodiment, the motor controller also needs to limit the superimposed signal of the vehicle instruction and the pulse torque compensation instruction before outputting the torque adjustment value. In addition, when the motor controller only receives the vehicle instruction, the motor controller also needs to limit the vehicle instruction to avoid exceeding the motor's output torque capacity.

[0039] S030. In each of the four-stroke cycles, the motor controller controls the motor to execute the torque adjustment value corresponding to the pulse compensation instruction according to the pulse compensation instruction and the vehicle instruction.

[0040] Specifically, since the engine periodically performs a four-stroke cycle, in each four-stroke cycle, the motor controller needs to control the motor to output the corresponding torque to drive the engine to continue the corresponding operation. After the monitoring program generates a pulse compensation instruction and a delay time T, the motor controller updates the value of the internal timer. When the delay time is not reached, the motor controller does not superimpose the pulse compensation torque instruction, but only responds to the vehicle instruction sent by the vehicle. When the delay time is reached, the motor controller superimposes the pulse torque compensation instruction on the torque instruction given by the vehicle to form a new torque instruction, and controls the motor to output the corresponding torque, thereby suppressing the engine vibration.

[0041] To summarize, the present invention constructs a delay function to determine the time when the engine jitters in each four-stroke cycle, and constructs a pulse torque compensation function to determine the compensation amplitude of the engine jitter, thereby ensuring that the engine can be suppressed and adjusted in time when it jitters in each four-stroke cycle.

[0042] The foregoing describes certain embodiments of the invention. Other embodiments are within the scope of the following claims.

[0043] The terms "exemplary," "example," and the like used throughout this specification mean "serving as an example, instance, or illustration" and do not mean "preferred" or "advantageous" over other embodiments. The detailed description includes specific details for the purpose of providing an understanding of the described techniques. However, the techniques may be implemented without these specific details. In some instances, in order to avoid obscuring the concepts of the described embodiments, well-known structures and devices are shown in block diagram form.

[0044] The optional implementation modes of the embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above implementation modes. Within the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all belong to the protection scope of the embodiments of the present invention.

[0045] The above description of the contents of this specification is provided to enable any person of ordinary skill in the art to implement or use the contents of this specification. Various modifications to the contents of this specification will be apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of protection of the contents of this specification. Therefore, the contents of this specification are not limited to the examples and designs described herein, but are consistent with the widest range of principles and novel features disclosed herein.

Claims

1. A method for suppressing engine vibration, characterized in that: The following steps are involved: Construct delay function and pulse torque compensation function; In each four-stroke cycle, an ignition signal is generated and a corresponding pulse signal is generated at the same time; The motor controller starts a monitoring program according to the pulse signal, and the monitoring program generates a pulse compensation instruction according to the delay function and the pulse torque compensation function; In each of the four-stroke cycles, the motor controller controls the motor to execute the torque adjustment value corresponding to the pulse compensation instruction according to the pulse compensation instruction and the vehicle instruction.

2. A method for suppressing engine vibration according to claim 1, characterized in that: The monitoring program includes the following steps: determining whether the current operating condition of the engine meets the compensation condition; Calculate and generate a delay time T according to the delay function; Calculate the torque adjustment value according to the pulse torque compensation function and generate the corresponding pulse compensation instruction; performing amplitude limiting processing on the pulse compensation instruction; The motor controller controls the motor to execute the torque adjustment value after the delay time T.

3. A method for suppressing engine vibration according to claim 2, characterized in that: The delay function includes the mapping relationship between the ignition signal and the engine jitter time difference under different motor speeds; the pulse torque compensation function iteratively optimizes the torque adjustment value by establishing an initial value, thereby establishing a mapping relationship based on the delay function; wherein each speed of the motor corresponds to one of the torque adjustment values.

4. A method for suppressing engine vibration according to claim 2, characterized in that: The compensation conditions include: the rotation speed of the motor is less than 50% of the peak rotation speed and greater than the idle rotation speed, and the motor controller fails.

5. A method for suppressing engine vibration according to claim 4, characterized in that: When the running state of the engine satisfies one of the compensation conditions, the monitoring program generates the compensation instruction; otherwise, the motor controller controls the motor execution torque only according to the vehicle instruction.

6. A method for suppressing engine vibration according to claim 5, characterized in that: In the four-stroke cycle, when the motor controller does not receive the pulse signal, the motor controller controls the motor to execute the torque adjustment value only according to the vehicle instruction.

7. A method for suppressing engine vibration according to claim 5, characterized in that: Before controlling the motor to execute the torque adjustment value, the motor controller also needs to perform a limiting process on the torque adjustment value.

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