Fully variable valve control method and engine system

Abstract

The invention discloses a fully variable valve control method and an engine system.The method comprises the steps that in the operation process of an engine, a first reference signal, a second reference signal and a current working condition signal of the engine are obtained; determining a target opening angle and a target closing angle of the valve according to the current working condition signal; according to the current working condition signal, the first reference signal, the second reference signal, the target opening angle and the target closing angle, the opening moment and the closing moment of the valve are determined; when the air valve is opened, the actual opening angle is obtained, and when the air valve is closed, the actual closing angle is obtained; according to the relation between the actual opening angle and the target opening angle and the relation between the actual closing angle and the target closing angle, the target opening angle and the target closing angle are corrected in real time, so that the actual opening angle is the same as the target opening angle, and the actual closing angle is the same as the target closing angle. By means of the method, accurate control over the valve angle is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and in particular to a control method of a fully variable valve and an engine system. Background Art

[0002] The valves of the engine are usually driven by the camshaft. For ordinary engines without variable valve timing technology, the opening and closing times of the intake and exhaust valves are fixed, but this fixed valve timing is difficult to take into account the needs of the engine at different speeds and working conditions. To this end, based on the requirements of improving the power, economy and emission reduction of automobile engines, the engine's fully variable valve timing technology has been gradually applied in recent years. The fully variable valve timing system can flexibly control the valve opening and closing angles by controlling the power-on and power-off moments of the solenoid valve according to the different operating requirements of the engine. The power-on and power-off moments of the solenoid valve are controlled based on the crankshaft signal. Once the crankshaft signal is wrong, it will cause a deviation in the driving time, which will lead to inaccurate valve opening and closing angles, and a serious accident of piston hitting the valve.

[0003] The existing valve control usually corrects the target angle according to the delay time of the actual opening angle and the actual closing angle under the premise of the correct driving reference signal, and compares it with the maximum delay time to determine whether there is an error. However, this method has a lag in judgment, and after a serious fault occurs, it cannot avoid the phenomenon of the piston hitting the valve, which affects the performance and service life of the engine system. Summary of the invention

[0004] The present invention provides a fully variable valve control method and an engine system, which utilize angle closed-loop control to achieve precise control of the valve opening angle and closing angle, avoid the phenomenon of piston hitting the valve, improve the performance and reliability of the engine system, and extend the service life of the engine system.

[0005] In a first aspect, the present invention provides a method for controlling a fully variable valve, which is applied to an engine system, wherein the system comprises a control unit, a crankshaft signal disk, a first crankshaft position sensor, a second crankshaft position sensor and a valve; the control unit is electrically connected to the crankshaft signal disk, the first crankshaft position sensor, the second crankshaft position sensor and the valve respectively, and the first crankshaft position sensor and the second crankshaft position sensor are respectively located on opposite sides of the crankshaft signal disk to detect the angular displacement of the crankshaft signal disk when the crankshaft signal disk rotates, and to generate a first reference signal and a second reference signal respectively;

[0006] The method is executed by a control unit, and the method includes:

[0007] During the operation of the engine, a first reference signal, a second reference signal, and a current operating condition signal of the engine are obtained;

[0008] Determine the target opening angle and target closing angle of the valve according to the current working condition signal;

[0009] Determine the opening time and closing time of the valve according to the current working condition signal, the first reference signal, the second reference signal, the target opening angle and the target closing angle;

[0010] When the valve is open, the actual opening angle of the valve is obtained, and when the valve is closed, the actual closing angle of the valve is obtained;

[0011] According to the relationship between the actual opening angle and the target opening angle, and the relationship between the actual closing angle and the target closing angle, the target opening angle and the target closing angle are corrected in real time so that the actual opening angle is the same as the target opening angle, and the actual closing angle is the same as the target closing angle.

[0012] Optionally, the current operating condition signal includes an engine speed signal and a target fuel injection amount signal; the target opening angle includes an intake valve target opening angle and an exhaust valve target opening angle, and the target closing angle includes an intake valve target closing angle and an exhaust valve target closing angle;

[0013] Determine the target opening angle and target closing angle of the valve according to the current working condition signal, including:

[0014] According to the engine speed signal and the target fuel injection amount signal, based on different preset corresponding relationships, the intake valve target opening angle, the exhaust valve target opening angle, the intake valve target closing angle and the exhaust valve target closing angle are determined respectively.

[0015] Optionally, determining the opening and closing times of the valve according to the current operating condition signal, the first reference signal, the second reference signal, the target opening angle, and the target closing angle includes:

[0016] Determine the valve opening and closing angle comparison value and the valve opening and closing time comparison value according to the current working condition signal, the first reference signal, the second reference signal, the target opening angle and the target closing angle;

[0017] The opening and closing times of the valves are determined based on the opening and closing angle comparison values ​​and the opening and closing time comparison values.

[0018] Optionally, the current operating condition signal includes an engine speed signal and an engine instantaneous acceleration signal; the opening and closing angle comparison values ​​include an intake valve first opening angle comparison value, an intake valve first closing angle comparison value, an exhaust valve first opening angle comparison value, an exhaust valve first closing angle comparison value, an intake valve second opening angle comparison value, an intake valve second closing angle comparison value, an exhaust valve second opening angle comparison value, and an exhaust valve second closing angle comparison value; the opening and closing time comparison values ​​include an intake valve first opening time comparison value, an intake valve first closing time comparison value, an exhaust valve first opening time comparison value, and an exhaust valve first closing time comparison value;

[0019] Determining a valve opening and closing angle comparison value and a valve opening and closing time comparison value according to a current operating condition signal, a first reference signal, a second reference signal, a target opening angle, and a target closing angle, including:

[0020] Determine, according to the first reference signal, the second reference signal, the target opening angle, and the target closing angle, a first intake valve opening angle comparison value, a first intake valve closing angle comparison value, a first exhaust valve opening angle comparison value, a first exhaust valve closing angle comparison value, a second intake valve opening angle comparison value, a second intake valve closing angle comparison value, a second exhaust valve opening angle comparison value, and a second exhaust valve closing angle comparison value;

[0021] According to the engine speed signal, the engine instantaneous acceleration signal, the target opening angle and the target closing angle, the intake valve first opening time comparison value, the intake valve first closing time comparison value, the exhaust valve first opening time comparison value and the exhaust valve first closing time comparison value are determined.

[0022] Optionally, the target opening angle includes an intake valve target opening angle and an exhaust valve target opening angle, and the target closing angle includes an intake valve target closing angle and an exhaust valve target closing angle;

[0023] Determining, according to the first reference signal, the second reference signal, the target opening angle, and the target closing angle, a first intake valve opening angle comparison value, a first intake valve closing angle comparison value, a first exhaust valve opening angle comparison value, a first exhaust valve closing angle comparison value, a second intake valve opening angle comparison value, a second intake valve closing angle comparison value, a second exhaust valve opening angle comparison value, and a second exhaust valve closing angle comparison value, including:

[0024] Determine an intake valve first opening angle comparison value, an intake valve first closing angle comparison value, an exhaust valve first opening angle comparison value, and an exhaust valve first closing angle comparison value according to the first reference signal, an intake valve target opening angle, an intake valve target closing angle, an exhaust valve target opening angle, and an exhaust valve target closing angle;

[0025] According to the second reference signal, the intake valve target opening angle, the intake valve target closing angle, the exhaust valve target opening angle and the exhaust valve target closing angle, the intake valve second opening angle comparison value, the intake valve second closing angle comparison value, the exhaust valve second opening angle comparison value and the exhaust valve second closing angle comparison value are determined.

[0026] Optionally, determining the opening and closing times of the valve according to the opening and closing angle comparison value and the opening and closing time comparison value includes:

[0027] Determining the opening timing of the intake valve and the opening timing of the exhaust valve according to the intake valve first opening angle comparison value, the exhaust valve first opening angle comparison value, the intake valve second opening angle comparison value, the exhaust valve second opening angle comparison value, the intake valve first opening time comparison value, and the exhaust valve first opening time comparison value;

[0028] The closing time of the intake valve and the closing time of the exhaust valve are determined based on the intake valve first closing angle comparison value, the exhaust valve first closing angle comparison value, the intake valve second closing angle comparison value, the exhaust valve second closing angle comparison value, the intake valve first closing time comparison value and the exhaust valve first closing time comparison value.

[0029] Optionally, determining the opening time of the intake valve and the opening time of the exhaust valve according to the intake valve first opening angle comparison value, the exhaust valve first opening angle comparison value, the intake valve second opening angle comparison value, the exhaust valve second opening angle comparison value, the intake valve first opening time comparison value, and the exhaust valve first opening time comparison value includes:

[0030] When the first opening angle comparison value of the intake valve and the first opening angle comparison value of the exhaust valve both meet the first preset opening angle condition, and the second opening angle comparison value of the intake valve and the second opening angle comparison value of the exhaust valve both meet the second preset opening angle condition, controlling the output of the opening pulse to open the intake valve and the exhaust valve;

[0031] When the intake valve and / or exhaust valve is not opened, according to the intake valve first opening time comparison value and / or the exhaust valve first opening time comparison value, when the intake valve first opening time comparison value meets the first preset opening time condition, and / or the exhaust valve first opening time comparison value meets the second preset opening time condition, the control outputs an opening pulse to open the intake valve and / or the exhaust valve.

[0032] Optionally, determining the closing time of the intake valve and the closing time of the exhaust valve according to the first closing angle comparison value of the intake valve, the first closing angle comparison value of the exhaust valve, the second closing angle comparison value of the intake valve, the second closing angle comparison value of the exhaust valve, the first closing time comparison value of the intake valve, and the first closing time comparison value of the exhaust valve includes:

[0033] When the first closing angle comparison value of the intake valve and the first closing angle comparison value of the exhaust valve both meet the first preset closing angle condition, or when the second closing angle comparison value of the intake valve and the second closing angle comparison value of the exhaust valve both meet the second preset closing angle condition, controlling the output of a closing pulse to close the intake valve and the exhaust valve;

[0034] When the intake valve and / or exhaust valve are not closed, according to the intake valve first closing time comparison value and / or the exhaust valve first closing time comparison value, when the intake valve first closing time comparison value meets the first preset closing time condition, and / or the exhaust valve first closing time comparison value meets the second preset closing time condition, the control outputs a closing pulse to close the intake valve and / or the exhaust valve.

[0035] Optionally, before acquiring the first reference signal and the second reference signal, the method further includes:

[0036] The first reference signal and the second reference signal are subjected to cylinder judgment and self-correction to determine the signal states of the first reference signal and the second reference signal.

[0037] In a second aspect, the present invention provides an engine system for implementing the above-mentioned fully variable valve control method.

[0038] The technical solution of the present invention is to obtain the first reference signal, the second reference signal, and the current working condition signal of the engine during the operation of the engine; determine the target opening angle and the target closing angle of the valve according to the current working condition signal; determine the opening time and the closing time of the valve according to the current working condition signal, the first reference signal, the second reference signal, the target opening angle and the target closing angle; obtain the actual opening angle of the valve when the valve is opened, and obtain the actual closing angle of the valve when the valve is closed; according to the relationship between the actual opening angle and the target opening angle, and the relationship between the actual closing angle and the target closing angle, the target opening angle and the target closing angle are corrected in real time, so that the actual opening angle is the same as the target opening angle, and the actual closing angle is the same as the target closing angle. According to the above method, the angle closed-loop control is used to realize the precise control of the valve opening angle and the closing angle, avoid the phenomenon of the piston hitting the valve, improve the performance and reliability of the engine system, and extend the service life of the engine system.

[0039] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 A flow chart of a fully variable valve control method provided by an embodiment of the present invention;

[0042] Figure 2 A signal schematic diagram of a first reference signal provided by an embodiment of the present invention;

[0043] Figure 3 A signal schematic diagram of a second reference signal provided by an embodiment of the present invention;

[0044] Figure 4 This is a flow chart of a second fully variable valve control method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0047] In one embodiment, Figure 1 A flow chart of a fully variable valve control method provided by an embodiment of the present invention, Figure 2 A signal schematic diagram of a first reference signal provided by an embodiment of the present invention, Figure 3A signal diagram of a second reference signal provided by an embodiment of the present invention, referring to Figures 1 to 3 As shown, this embodiment can be applied to accurately control the opening angle and closing angle of the valve to avoid the piston hitting the valve. The method can be executed by a fully variable valve control device, and the fully variable valve control device can be implemented in the form of hardware and / or software. The fully variable valve control device can be configured in the engine system. In this embodiment, the engine system includes a control unit, a crankshaft signal disk, a first crankshaft position sensor, a second crankshaft position sensor and a valve; the control unit is electrically connected to the crankshaft signal disk, the first crankshaft position sensor, the second crankshaft position sensor and the valve, respectively, and the first crankshaft position sensor and the second crankshaft position sensor are respectively located on opposite sides of the crankshaft signal disk, that is, the installation position of the first crankshaft position sensor differs by 180° from the installation position of the second crankshaft position sensor. During the operation of the engine, refer to Figure 2 and Figure 3 As shown, the crankshaft signal disk will rotate. When the engine works for one cycle, the crankshaft signal disk will rotate two circles. When the crankshaft signal disk rotates, the first crankshaft position sensor and the second crankshaft position sensor will detect the angular displacement of the crankshaft signal disk in real time, and generate the first reference signal Ne1 and the second reference signal Ne2 respectively according to the angular displacement.

[0048] The control method is executed by a control unit, and the control method includes:

[0049] S110 . During the operation of the engine, a first reference signal, a second reference signal, and a current operating condition signal of the engine are obtained.

[0050] The current working condition signal of the engine may include but is not limited to the engine speed, the fuel injection amount of the engine, and the instantaneous acceleration of the engine, etc. The specific conditions may be determined according to the actual situation and are not limited here.

[0051] Specifically, after the first crankshaft position sensor generates a first reference signal and the second crankshaft position sensor generates a second reference signal, the first reference signal and the second reference signal are acquired, and at the same time, the current operating condition signal of the engine is acquired. The current operating condition signal can be acquired based on but not limited to acquisition through corresponding sensors.

[0052] S120: Determine a target opening angle and a target closing angle of the valve according to a current operating condition signal.

[0053] Specifically, after obtaining the current operating condition signal of the engine, the target opening angle of the valve and the target closing angle of the valve can be determined according to the current operating condition of the engine by using the preset corresponding relationship. Usually, the valve includes an intake valve and an exhaust valve, that is, the target opening angle and the target closing angle of the valve include the target opening angle and the target closing angle of the intake valve, and the target opening angle and the target closing angle of the exhaust valve. In addition, the target opening angle and the target closing angle of the valve calculated in this step are the expected angle target values ​​of the valve.

[0054] S130, determining the opening time and closing time of the valve according to the current operating condition signal, the first reference signal, the second reference signal, the target opening angle and the target closing angle.

[0055] The valve opening time is the agreed opening time of the valve, that is, when the valve is expected to open. Similarly, the valve closing time is the agreed closing time of the valve, that is, when the valve is expected to close. In this embodiment, in order to ensure system safety, the valve cannot be opened in advance, but can be closed in advance.

[0056] Specifically, after determining the target opening angle and target closing angle of the outlet valve, the opening and closing angle comparison value of the outlet valve can be determined according to the first reference signal, the second reference signal, the target opening angle and the target closing angle of the valve. According to the current working condition signal, the target opening angle and the target closing angle of the valve, the opening and closing time comparison value of the outlet valve can be determined. After determining the opening and closing angle comparison value and the opening and closing time comparison value, the opening and closing time of the outlet valve can be determined according to the preset logical judgment.

[0057] S140, when the valve is open, obtaining the actual opening angle of the valve, and when the valve is closed, obtaining the actual closing angle of the valve.

[0058] The actual opening angle of the valve is the angle at which the valve is actually opened when it is opened, and the actual closing angle of the valve is the angle at which the valve is actually closed when it is closed. The acquisition of the actual opening angle and the actual closing angle of the valve can include but are not limited to acquisition through a valve position sensor, which is not limited here.

[0059] Specifically, after determining the opening moment of the valve, the intake valve or exhaust valve will be controlled to open to the corresponding target opening angle. However, due to some reasons, a certain angle error will inevitably occur during the actual opening process, making the actual opening angle of the intake valve or exhaust valve different from the target opening angle. Therefore, in order to determine the actual opening angle, the actual opening angle of the intake valve and the exhaust valve can be obtained after the intake valve or the exhaust valve is opened. For example, the target opening angle is 10°, and the actual opening angle obtained is 8°. Similarly, after determining the closing moment of the valve, the intake valve or the exhaust valve will be controlled to close from the target opening angle. However, due to some reasons, a certain angle error will inevitably occur during the actual closing process, making the actual closing angle of the intake valve or the exhaust valve different from the target closing angle. Therefore, in order to determine the actual closing angle, the actual closing angle of the intake valve and the exhaust valve can be obtained after the intake valve or the exhaust valve is closed. For example, the target closing angle is 10°, and the actual closing angle obtained is 8°, that is, the valve is not completely closed.

[0060] S150. According to the relationship between the actual opening angle and the target opening angle, and the relationship between the actual closing angle and the target closing angle, the target opening angle and the target closing angle are corrected in real time so that the actual opening angle is the same as the target opening angle, and the actual closing angle is the same as the target closing angle.

[0061] Specifically, after obtaining the actual opening angle and the actual closing angle of the valve, it is necessary to correct the target opening angle and the target closing angle in real time based on the relationship between the actual opening angle and the target opening angle, and the relationship between the actual closing angle and the target closing angle, when there is an angle difference between the actual opening angle and the target opening angle, and when there is an angle difference between the actual closing angle and the target closing angle, based on the difference, to achieve closed-loop control of the opening angle. Taking the real-time correction of the target opening angle as an example, the target opening angle is 10°, and the actual opening angle obtained after the valve is opened is 8°. It can be seen that the angle difference between the actual opening angle and the target opening angle is -2°. Therefore, when correcting the target opening angle, the angle difference can be compensated to the target opening angle, that is, the target opening angle is corrected to 8°. In the next engine cycle, the target opening angle is 8°. After the target opening angle is corrected, the corresponding valve opening time and the actual opening angle will be changed accordingly. After multiple cycles, the target opening angle is finally corrected to the same as the actual opening angle obtained, which means that the real-time correction process is over, and the subsequent control is always based on the final corrected target opening angle. When the target closing angle is corrected, the correction logic is the same as the correction logic of the target opening angle, and the target opening angle can be referred to, which will not be described in detail. The closed-loop control logic improves the control accuracy of the valve opening angle and closing angle.

[0062] The technical solution of the embodiment of the present invention is to obtain the first reference signal, the second reference signal, and the current working condition signal of the engine during the operation of the engine; determine the target opening angle and the target closing angle of the valve according to the current working condition signal; determine the opening time and the closing time of the valve according to the current working condition signal, the first reference signal, the second reference signal, the target opening angle and the target closing angle; obtain the actual opening angle of the valve when the valve is opened, and obtain the actual closing angle of the valve when the valve is closed; according to the relationship between the actual opening angle and the target opening angle, and the relationship between the actual closing angle and the target closing angle, the target opening angle and the target closing angle are corrected in real time, so that the actual opening angle is the same as the target opening angle, and the actual closing angle is the same as the target closing angle. According to the above method, the angle closed-loop control is used to realize the precise control of the valve opening angle and the closing angle, avoid the phenomenon of the piston hitting the valve, improve the performance and reliability of the engine system, and extend the service life of the engine system.

[0063] Figure 4 Flow chart of a second fully variable valve control method provided in an embodiment of the present invention. This embodiment refines the specific implementation method of how to control the opening and closing time of the valve in the above embodiment. Figures 2 to 4 As shown, the method includes:

[0064] S210 , performing cylinder judgment and self-calibration on the first reference signal and the second reference signal to determine the signal states of the first reference signal and the second reference signal.

[0065] Among them, cylinder determination is the process of determining the precise position of each cylinder of the engine through the joint work of the crankshaft position sensor and the camshaft position sensor during the operation of the engine. For the crankshaft position sensor, there will be one or more missing teeth on the crankshaft signal disk detected by the crankshaft position sensor, and these missing teeth correspond to the top dead center position of a specific cylinder. When the crankshaft position sensor detects a missing tooth signal, it means that it has identified a specific position of the crankshaft signal disk, usually a specific angle before the top dead center of the first cylinder or the fourth cylinder, indicating that the cylinder determination has been completed.

[0066] Specifically, after the first crankshaft position sensor generates the first reference signal Ne1 and the second crankshaft position sensor generates the second reference signal Ne2, it is necessary to perform cylinder determination and self-calibration on the first reference signal Ne1 and the second reference signal Ne2. Figure 2 and Figure 3As shown, taking a 4-cylinder 4-stroke engine as an example, the crankshaft signal disk has a tooth shape of 60-2, that is, there are 58 normal teeth and 1 missing tooth when the crankshaft rotates one circle, and 1 missing tooth includes two normal teeth. The engine works for one cycle, and the crankshaft signal disk rotates two circles. The first crankshaft position sensor and the second crankshaft position sensor will detect 4 missing teeth during the process of the crankshaft signal disk rotating two circles, which are the first missing tooth 31 and the second missing tooth 32 of the first reference signal Ne1, and the third missing tooth 41 and the fourth missing tooth 42 of the second reference signal Ne2. When any missing tooth is detected, it is judged that the cylinder is completed. At this time, the angle of the first normal tooth after the first missing tooth 31 is taken as the working reference 0 degree, and the angle of the first normal tooth after the third missing tooth 41 is 180°. In addition, after the cylinder judgment is completed, the first reference signal Ne1 and the second reference signal Ne2 need to be self-calibrated. That is to say, after the first reference signal Ne1 is generated, the number of normal teeth between the first missing tooth 31 and the second missing tooth 32, that is, the number of pulse signals, needs to be confirmed. If it is confirmed that the number of normal teeth is less than 58, the missing normal teeth will be automatically filled in during the self-calibration process to keep the number of normal teeth at 58. When it is confirmed that the number of normal teeth is greater than 58, such as 59, each normal tooth, that is, the pulse signal, will be determined during the self-calibration process. When it is determined that a pulse signal is abnormal, the abnormal pulse signal will be automatically eliminated to ensure that the number of normal teeth remains at 58. Similarly, the self-calibration of the second reference signal Ne2 is the same as the self-calibration process of the first reference signal Ne1. The self-calibration process of the first reference signal Ne1 can be referred to, and will not be repeated here.

[0067] S211. During the operation of the engine, a first reference signal, a second reference signal, and a current operating condition signal of the engine are obtained.

[0068] Among them, the current working condition signal includes an engine speed signal, a target fuel injection amount signal and an engine instantaneous acceleration signal. The acquisition of the engine speed signal may include but is not limited to acquisition through a speed sensor, or may be determined based on normal teeth and missing teeth on the first reference signal and the second reference signal. The acquisition of the target fuel injection amount signal may be determined and acquired based on the engine speed, using a preset corresponding relationship between the engine speed and the target fuel injection amount, and the acquisition of the engine instantaneous acceleration signal may include but is not limited to acquisition through an acceleration sensor.

[0069] S212, according to the engine speed signal and the target fuel injection amount signal, based on different preset corresponding relationships, respectively determine the intake valve target opening angle, the exhaust valve target opening angle, the intake valve target closing angle and the exhaust valve target closing angle.

[0070] Specifically, after the engine speed signal and the target fuel injection amount signal are obtained, based on the first preset corresponding relationship, the first preset corresponding relationship is the corresponding relationship between the engine speed signal and the target fuel injection amount signal and the target opening angle of the intake valve. After the engine speed signal and the target fuel injection amount signal are determined, after being input into the first preset corresponding relationship, the corresponding target opening angle of the intake valve can be determined. Similarly, based on the second preset corresponding relationship, the second preset corresponding relationship is the corresponding relationship between the engine speed signal and the target fuel injection amount signal and the target opening angle of the exhaust valve, the engine speed signal and the target fuel injection amount signal can be input into the second preset corresponding relationship, thereby determining the corresponding target opening angle of the exhaust valve. Based on the third preset corresponding relationship, the third preset corresponding relationship is the corresponding relationship between the engine speed signal and the target fuel injection amount signal and the target closing angle of the intake valve. The engine speed signal and the target fuel injection amount signal can be input into the third preset corresponding relationship, thereby determining the corresponding target closing angle of the intake valve. Based on the fourth preset corresponding relationship, the fourth preset corresponding relationship is the corresponding relationship between the engine speed signal and the target fuel injection amount signal and the target closing angle of the exhaust valve. The engine speed signal and the target fuel injection amount signal may be input into a fourth preset corresponding relationship, thereby determining a corresponding exhaust valve target closing angle.

[0071] S213, determining the valve opening and closing angle comparison value and the valve opening and closing time comparison value according to the current operating condition signal, the first reference signal, the second reference signal, the target opening angle, and the target closing angle.

[0072] Among them, the opening and closing angle comparison values ​​include the first opening angle comparison value of the intake valve, the first closing angle comparison value of the intake valve, the first opening angle comparison value of the exhaust valve, the first closing angle comparison value of the exhaust valve, the second opening angle comparison value of the intake valve, the second closing angle comparison value of the intake valve, the second opening angle comparison value of the exhaust valve and the second closing angle comparison value of the exhaust valve; the opening and closing time comparison values ​​include the first opening time comparison value of the intake valve, the first closing time comparison value of the intake valve, the first opening time comparison value of the exhaust valve and the first closing time comparison value of the exhaust valve.

[0073] Among them, this step can be further refined into: determining the first opening angle comparison value of the intake valve, the first closing angle comparison value of the intake valve, the first opening angle comparison value of the exhaust valve, the first closing angle comparison value of the exhaust valve, the second opening angle comparison value of the intake valve, the second closing angle comparison value of the exhaust valve, and the second opening angle comparison value of the exhaust valve according to the first reference signal, the second reference signal, the target opening angle and the target closing angle; determining the first opening time comparison value of the intake valve, the first closing time comparison value of the intake valve, the first opening time comparison value of the exhaust valve and the first closing time comparison value of the exhaust valve according to the engine speed signal, the engine instantaneous acceleration signal, the target opening angle and the target closing angle.

[0074] Among them, the opening and closing angle comparison value is a numerical value corresponding to the target opening angle and the target closing angle, except that the target opening angle and the target closing angle are numerical values ​​with actual physical meanings, and the opening and closing angle comparison value is set in the comparator or timer to convert the target opening angle and the target closing angle into a numerical value input into the comparator or timer for comparison. The opening and closing time comparison value is a time value calculated based on the engine speed, instantaneous acceleration, target opening angle and target closing angle. The target opening angle includes the intake valve target opening angle and the exhaust valve target opening angle, and the target closing angle includes the intake valve target closing angle and the exhaust valve target closing angle.

[0075] Specifically, when determining the opening and closing angle comparison value corresponding to the first reference signal, the first reference signal can be combined with the target opening angle and the target closing angle, that is, the intake valve target opening angle, the intake valve target closing angle, the exhaust valve target opening angle, and the exhaust valve target closing angle, and the actual position of the normal tooth and the missing tooth can be determined according to the first reference signal, and each tooth position will correspond to a comparator value. Under normal circumstances, when a tooth is displayed on the comparator, the tooth signal will be divided into 100 parts, such as the comparator value corresponding to the first tooth is 100, the comparator value corresponding to the second tooth is 200, and so on. At this time, according to the determined intake valve target opening angle, intake valve target closing angle, exhaust valve target opening angle, and exhaust valve target closing angle, there is a preset corresponding relationship between each angle and the tooth, so according to the above target opening angle and target closing angle, the corresponding tooth position can be determined, and the comparator value corresponding to the tooth position can be determined according to the tooth position, thereby determining the intake valve first opening angle comparison value, the intake valve first closing angle comparison value, the exhaust valve first opening angle comparison value, and the exhaust valve first closing angle comparison value. For example, taking the first opening time comparison value of the intake valve as an example, the crankshaft signal disk has 60 teeth in one rotation, and the angle of one rotation is 360°, that is, each tooth corresponds to an angle of 6°. If the target opening angle of the intake valve is 12°, only 2 teeth are needed, and these two teeth will be converted into the value of the comparator, that is, 200. Therefore, the value of the comparator 200 is the determined first opening time comparison value of the intake valve, which indicates that the target opening angle of the intake valve is 12°.

[0076] Similarly, when determining the opening and closing angle comparison value corresponding to the second reference signal, the actual positions of the normal teeth and the missing teeth can be determined based on the second reference signal in combination with the target opening angle and the target closing angle, i.e., the intake valve target opening angle, the intake valve target closing angle, the exhaust valve target opening angle, and the exhaust valve target closing angle, and the actual positions of the normal teeth and the missing teeth can be determined according to the second reference signal, and the position of each tooth will correspond to a comparator value. Under normal circumstances, when one tooth is displayed on the comparator, the tooth signal will be divided into 100 parts, such as the comparator value corresponding to the first tooth is 100, the comparator value corresponding to the second tooth is 200, and so on. At this time, according to the determined intake valve target opening angle, intake valve target closing angle, exhaust valve target opening angle, and exhaust valve target closing angle, each angle has a corresponding relationship with the tooth, so according to the above target opening angle and target closing angle, the position of the tooth corresponding to each can be determined, and the comparator value corresponding to the position of the tooth can be determined according to the position of the tooth, thereby determining the intake valve second opening angle comparison value, the intake valve second closing angle comparison value, the exhaust valve second opening angle comparison value, and the exhaust valve second closing angle comparison value.

[0077] After determining the opening angle comparison value, it is also necessary to determine the opening and closing time comparison value. In the present embodiment, according to the engine speed signal, the instantaneous acceleration signal, combined with the intake valve target opening angle, the intake valve target closing angle, the exhaust valve target opening angle and the exhaust valve target closing angle, a conversion relationship similar to the above method is used, that is, the engine speed signal and the instantaneous acceleration signal can be determined according to the position of the teeth, and the intake valve target opening angle, the intake valve target closing angle, the exhaust valve target opening angle and the exhaust valve target closing angle also have a preset corresponding relationship with the position of the teeth, and the position of the teeth also has a corresponding relationship with the value of the comparator. Therefore, the position of the teeth is used as a conversion medium to finally determine the first opening time comparison value of the intake valve, the first closing time comparison value of the intake valve, the first opening time comparison value of the exhaust valve and the first closing time comparison value of the exhaust valve.

[0078] S214, determining the opening time and closing time of the valve according to the opening and closing angle comparison value and the opening and closing time comparison value.

[0079] Among them, this step can be further refined into: determining the opening time of the intake valve and the opening time of the exhaust valve according to the first opening angle comparison value of the intake valve, the first opening angle comparison value of the exhaust valve, the second opening angle comparison value of the intake valve, the second opening angle comparison value of the exhaust valve, the first opening time comparison value of the intake valve and the first opening time comparison value of the exhaust valve; determining the closing time of the intake valve and the closing time of the exhaust valve according to the first closing angle comparison value of the intake valve, the first closing angle comparison value of the exhaust valve, the second closing angle comparison value of the intake valve, the second closing angle comparison value of the exhaust valve, the first closing time comparison value of the intake valve and the first closing time comparison value of the exhaust valve.

[0080] Specifically, after determining the opening and closing angle comparison value and the opening and closing time comparison value, it is necessary to determine the opening time and closing time of the valve. In this embodiment, when determining the opening time of the intake valve and the opening time of the exhaust valve, the first opening angle comparison value of the intake valve and the first opening angle comparison value of the exhaust valve can be used. When the first opening angle comparison value of the intake valve and the first opening angle comparison value of the exhaust valve both meet the corresponding first preset opening angle conditions, the first preset opening angle conditions are that the first opening angle comparison value of the intake valve is the same as the angle corresponding to the teeth of the crankshaft signal disk that has been circulated and rotated in the first timer, and the first opening angle comparison value of the exhaust valve is the same as the angle corresponding to the teeth of the crankshaft signal disk that has been circulated and rotated in the first timer, indicating that the signal output of the first opening angle comparison value of the intake valve and the first opening angle comparison value of the exhaust valve is normal at this time. At this time, based on the second opening angle comparison value of the intake valve and the second opening angle comparison value of the exhaust valve, when the second opening angle comparison value of the intake valve and the second opening angle comparison value of the exhaust valve both meet the corresponding second preset opening angle conditions, the second preset opening angle conditions are that the second opening angle comparison value of the intake valve is the same as the angle corresponding to the teeth of the crankshaft signal disk that has been rotating in a cycle in the second timer, and the second opening angle comparison value of the exhaust valve is the same as the angle corresponding to the teeth of the crankshaft signal disk that has been rotating in a cycle in the second timer, indicating that the signal outputs of the second opening angle comparison value of the intake valve and the second opening angle comparison value of the exhaust valve are normal at this time, and the opening conditions of the intake valve and the exhaust valve are met. Only when the first opening angle comparison value of the intake valve, the first opening angle comparison value of the exhaust valve, the second opening angle comparison value of the intake valve and the second opening angle comparison value of the exhaust valve all meet the corresponding preset opening angle conditions, that is, when the logical relationship of "and" is met, it indicates that the opening angle pulses output by the first opening angle comparison value of the intake valve, the first opening angle comparison value of the exhaust valve, the second opening angle comparison value of the intake valve and the second opening angle comparison value of the exhaust valve are triggered at the same time. At this time, the intake valve and the exhaust valve can be opened safely without the phenomenon of the valve hitting the piston. The output opening pulse is controlled to open the intake valve and the exhaust valve to the target opening angle. In addition, when the opening pulse is output, the time between the moment when the output opening pulse is triggered and the moment when the opening pulse is actually output will be counted. After the counting time reaches the preset opening time, the intake valve and / or exhaust valve has not been opened. At this time, the opening of the intake valve and / or exhaust valve will be controlled according to the opening and closing time comparison value to ensure that the intake valve and / or exhaust valve is opened; when the intake valve and the exhaust valve are both open after the time reaches the preset opening time, the opening and closing time comparison value will be ignored and only exists as a protection logic, which will not affect the valve opening. At this time, the opening time pulse output by the first opening time comparison value of the intake valve and the first opening time comparison value of the exhaust valve will be delayed by a certain time compared to the output opening angle pulse.Specifically, when the intake valve is not opened, according to the first opening time comparison value of the intake valve, when the first opening time comparison value of the intake valve meets the first preset opening time condition, that is, when the preset opening time corresponding to the opening of the intake valve is reached, it indicates that the intake valve has reached the opening time at this time, and a high-level opening pulse will be triggered to control the opening of the intake valve. When the exhaust valve is not opened, according to the first opening time comparison value of the exhaust valve, when the first opening time comparison value of the exhaust valve meets the second preset opening time condition, that is, when the preset opening time corresponding to the opening of the exhaust valve is reached, it indicates that the exhaust valve has reached the opening time at this time, and a high-level opening pulse will be triggered to control the opening of the exhaust valve. Ensure that the opening of the intake valve and the exhaust valve will not be abnormally early.

[0081] It should be noted that the above embodiment describes the determination of the opening time of the intake valve and the opening time of the exhaust valve at the same time. In fact, when controlling the opening of the intake valve, only the relationship between the first opening angle comparison value of the intake valve, the second opening angle comparison value of the intake valve, and the first opening time comparison value of the intake valve and the corresponding preset conditions is paid attention to. When the first opening angle comparison value of the intake valve meets the first preset opening angle condition, and the second opening angle comparison value of the intake valve meets the second preset opening angle condition, the intake valve can be controlled to open. When the intake valve is still not opened after the output opening pulse passes the preset opening time, the intake valve is controlled to open according to the first opening time comparison value of the intake valve, when the first opening time comparison value of the intake valve reaches the first preset opening time condition. Similarly, when controlling the opening of the exhaust valve, only the relationship between the first opening angle comparison value of the exhaust valve, the second opening angle comparison value of the exhaust valve, and the first opening time comparison value of the exhaust valve and the corresponding preset conditions is paid attention to. When the first opening angle comparison value of the exhaust valve meets the first preset opening angle condition, and the second opening angle comparison value of the exhaust valve meets the second preset opening angle condition, the exhaust valve can be controlled to open. When the exhaust valve reaches the preset opening time but is not opened, the exhaust valve is controlled to open according to the exhaust valve first opening time comparison value. When the exhaust valve first opening time comparison value reaches the second preset opening time condition, the exhaust valve is controlled to open.

[0082] In addition, when determining the closing time of the intake valve, when the first closing angle comparison value of the intake valve meets the first preset closing angle condition, the first preset opening angle condition is that the first closing angle comparison value of the intake valve is the same as the angle corresponding to the teeth of the crankshaft signal disk that has been cyclically rotating in the first timer, or when the second closing angle comparison value of the intake valve meets the second preset closing angle condition, the second preset opening angle condition is that the second closing angle comparison value of the intake valve is the same as the angle corresponding to the teeth of the crankshaft signal disk that has been cyclically rotating in the first timer, that is, when the "or" logical condition is satisfied, it indicates that the intake valve has reached the closing condition, and at this time, the output closing pulse can be controlled to close the intake valve. When the intake valve has not been closed from the output closing pulse to the preset closing time, the intake valve is controlled to be closed according to the first closing time comparison value of the intake valve to ensure that the intake valve is closed in time; when the intake valve is closed from the output closing pulse to the preset closing time, the first closing time comparison value of the intake valve is ignored. At this time, the first closing angle comparison value of the intake valve only exists as a protection logic and will not affect the closing of the intake valve. At this time, the closing time pulse output by the intake valve is delayed compared with the closing angle pulse. When the intake valve does not close within the preset closing time, the control outputs a closing pulse to close the intake valve based on the first closing time comparison value of the intake valve. When the first closing time comparison value of the intake valve satisfies the first preset closing time condition, the first preset closing time condition is the preset closing time corresponding to the closing of the intake valve, indicating that the latest closing time of the intake valve has been reached.

[0083] Similarly, when determining the closing time of the exhaust valve, when the exhaust valve first closing angle comparison value satisfies the first preset closing angle condition, the first preset opening angle condition is that the exhaust valve first closing angle comparison value is the same as the angle corresponding to the teeth of the crankshaft signal disk that has been cyclically rotating in the first timer, or when the exhaust valve second closing angle comparison value satisfies the second preset closing angle condition, the second preset opening angle condition is that the exhaust valve second closing angle comparison value is the same as the angle corresponding to the teeth of the crankshaft signal disk that has been cyclically rotating in the first timer, indicating that the exhaust valve has reached the closing condition, and the output closing pulse can be controlled at this time to close the exhaust valve. If the exhaust valve has not been closed from the output closing pulse to the preset closing time, the exhaust valve is controlled to be closed according to the exhaust valve first closing time comparison value to ensure that the exhaust valve is closed in time; if the exhaust valve is closed from the output closing pulse to the preset closing time, the exhaust valve first closing time comparison value is ignored. At this time, the exhaust valve first closing angle comparison value only exists as a protection logic and will not affect the closing of the exhaust valve, that is, the closing time pulse output by the exhaust valve is delayed compared with the closing angle pulse. When the exhaust valve is not closed within the preset closing time, the first closing time comparison value of the exhaust valve is used. When the first closing time comparison value of the exhaust valve satisfies the first preset closing time condition, the first preset closing time condition is the preset closing time corresponding to the exhaust valve closing time, indicating that the latest closing time of the exhaust valve has been reached, and the control outputs a closing pulse to close the exhaust valve, thereby ensuring that the intake valve and the exhaust valve will not be abnormally closed late.

[0084] In addition, when the first reference signal and the second reference signal are abnormal, for example, the first reference signal completes the cylinder judgment, but the second reference signal does not complete the cylinder judgment, if the second reference signal is faulty or abnormal, the abnormal second reference signal will be diagnosed. At this time, the abnormal second reference signal may be triggered in advance, but the normal first reference signal has not been triggered. At this time, after receiving the first reference signal and the second reference signal, the intake valve and the exhaust valve will not be controlled to open, but the intake valve and the exhaust valve will be opened and controlled according to the first opening time comparison value of the intake valve and the first opening time comparison value of the exhaust valve. As for controlling the closing of the intake valve and the exhaust valve, they can be closed in advance. Therefore, even if the second reference signal is triggered abnormally early, that is, it opens and closes earlier than the first reference signal, the intake valve and the exhaust valve can be controlled to close. At this time, the intake valve first closing time comparison value and the exhaust valve first closing time comparison value are ignored. In addition, while controlling the opening and closing of the intake valve and the exhaust valve, the faulty or abnormal second reference signal will be detected and reported to timely troubleshoot the cause of the abnormality.

[0085] In addition, when both the first reference signal and the second reference signal have completed cylinder judgment, but one of the reference signals is abnormally triggered prematurely but does not respond, for safety reasons, the other reference signal with normal signal is used as the judgment standard to judge the opening control of the intake valve and exhaust valve. If the signal is normal, the second opening angle comparison value of the intake valve, the second opening angle comparison value of the exhaust valve, the second closing angle comparison value of the intake valve and the second closing angle comparison value of the exhaust valve are judged. When the corresponding preset opening angle condition is met, the intake valve and / or exhaust valve is controlled to open. When the corresponding preset closing angle condition is met, the intake valve and / or exhaust valve is controlled to close.

[0086] In addition, when there are abnormalities in both the first reference signal and the second reference signal, such as signal lags in both the first reference signal and the second reference signal, the opening and closing angle comparison values ​​are unreliable. In this case, when controlling the opening and closing of the intake valve and the exhaust valve, it is necessary to determine the opening and closing based on the opening and closing time comparison values. The specific logic can be referred to the above description, which will not be repeated here.

[0087] S215. When the valve is open, obtain the actual opening angle of the valve; and when the valve is closed, obtain the actual closing angle of the valve.

[0088] S216. According to the relationship between the actual opening angle and the target opening angle, and the relationship between the actual closing angle and the target closing angle, the target opening angle and the target closing angle are corrected in real time so that the actual opening angle is the same as the target opening angle, and the actual closing angle is the same as the target closing angle.

[0089] The technical solution of the embodiment of the present invention determines the signal states of the first reference signal and the second reference signal by judging the cylinder and self-correcting the first reference signal and the second reference signal; determines the target opening angle of the intake valve, the target opening angle of the exhaust valve, the target closing angle of the intake valve and the target closing angle of the exhaust valve respectively based on different preset corresponding relationships according to the engine speed signal and the target fuel injection amount signal; determines the opening and closing angle comparison value and the opening and closing time comparison value of the valve according to the current working condition signal, the first reference signal, the second reference signal, the target opening angle and the target closing angle; determines the opening and closing time of the valve according to the opening and closing angle comparison value and the opening and closing time comparison value. Using the above method, according to the preset control logic, the precise control of the opening and closing time of the intake and exhaust valves is realized, ensuring that the intake and exhaust valves will not open prematurely, but can be closed prematurely, thereby improving the safety and reliability of the engine system and increasing the service life of the engine system.

[0090] Based on the same inventive concept, an embodiment of the present invention further provides an engine system for implementing the above-mentioned fully variable valve control method, having functional modules and beneficial effects corresponding to the execution method.

[0091] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0092] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fully variable valve control method, characterized in that: Applied in an engine system, the system comprises a control unit, a crankshaft signal disk, a first crankshaft position sensor, a second crankshaft position sensor and a valve; the control unit is electrically connected to the crankshaft signal disk, the first crankshaft position sensor, the second crankshaft position sensor and the valve respectively, the first crankshaft position sensor and the second crankshaft position sensor are respectively located on opposite sides of the crankshaft signal disk, so as to detect the angular displacement of the crankshaft signal disk when the crankshaft signal disk rotates, and respectively generate a first reference signal and a second reference signal; The method is executed by the control unit, and the method comprises: During the operation of the engine, acquiring the first reference signal, the second reference signal, and a current operating condition signal of the engine; Determining a target opening angle and a target closing angle of the valve according to the current operating condition signal; Determining the opening time and closing time of the valve according to the current operating condition signal, the first reference signal, the second reference signal, the target opening angle and the target closing angle; When the valve is open, obtaining the actual opening angle of the valve, and when the valve is closed, obtaining the actual closing angle of the valve; According to the relationship between the actual opening angle and the target opening angle, and the relationship between the actual closing angle and the target closing angle, the target opening angle and the target closing angle are corrected in real time so that the actual opening angle is the same as the target opening angle, and the actual closing angle is the same as the target closing angle.

2. The control method according to claim 1, characterized in that: The current operating condition signal includes an engine speed signal and a target fuel injection amount signal; the target opening angle includes an intake valve target opening angle and an exhaust valve target opening angle, and the target closing angle includes an intake valve target closing angle and an exhaust valve target closing angle; Determining a target opening angle and a target closing angle of the valve according to the current operating condition signal includes: According to the engine speed signal and the target fuel injection amount signal, based on different preset corresponding relationships, the intake valve target opening angle, the exhaust valve target opening angle, the intake valve target closing angle and the exhaust valve target closing angle are respectively determined.

3. The control method according to claim 1, characterized in that: Determining the opening time and closing time of the valve according to the current operating condition signal, the first reference signal, the second reference signal, the target opening angle, and the target closing angle, comprises: Determine an opening and closing angle comparison value and an opening and closing time comparison value of the valve according to the current operating condition signal, the first reference signal, the second reference signal, the target opening angle, and the target closing angle; The opening time and closing time of the valve are determined according to the opening and closing angle comparison value and the opening and closing time comparison value.

4. The control method according to claim 3, characterized in that: The current operating condition signal includes an engine speed signal and an engine instantaneous acceleration signal; the opening and closing angle comparison values ​​include an intake valve first opening angle comparison value, an intake valve first closing angle comparison value, an exhaust valve first opening angle comparison value, an exhaust valve first closing angle comparison value, an intake valve second opening angle comparison value, an intake valve second closing angle comparison value, an exhaust valve second opening angle comparison value, and an exhaust valve second closing angle comparison value; the opening and closing time comparison values ​​include an intake valve first opening time comparison value, an intake valve first closing time comparison value, an exhaust valve first opening time comparison value, and an exhaust valve first closing time comparison value; Determining the opening and closing angle comparison value and the opening and closing time comparison value of the valve according to the current operating condition signal, the first reference signal, the second reference signal, the target opening angle, and the target closing angle, including: Determining the intake valve first opening angle comparison value, the intake valve first closing angle comparison value, the exhaust valve first opening angle comparison value, the exhaust valve first closing angle comparison value, the intake valve second opening angle comparison value, the intake valve second closing angle comparison value, the exhaust valve second opening angle comparison value, and the exhaust valve second closing angle comparison value according to the first reference signal, the second reference signal, the target opening angle, and the target closing angle; The intake valve first opening time comparison value, the intake valve first closing time comparison value, the exhaust valve first opening time comparison value and the exhaust valve first closing time comparison value are determined according to the engine speed signal, the engine instantaneous acceleration signal, the target opening angle and the target closing angle.

5. The control method according to claim 4, characterized in that: The target opening angle includes an intake valve target opening angle and an exhaust valve target opening angle, and the target closing angle includes an intake valve target closing angle and an exhaust valve target closing angle; Determining the intake valve first opening angle comparison value, the intake valve first closing angle comparison value, the exhaust valve first opening angle comparison value, the exhaust valve first closing angle comparison value, the intake valve second opening angle comparison value, the intake valve second closing angle comparison value, the exhaust valve second opening angle comparison value, and the exhaust valve second closing angle comparison value according to the first reference signal, the second reference signal, the target opening angle, and the target closing angle, comprises: determining the intake valve first opening angle comparison value, the intake valve first closing angle comparison value, the exhaust valve first opening angle comparison value, and the exhaust valve first closing angle comparison value according to the first reference signal, the intake valve target opening angle, the intake valve target closing angle, the exhaust valve target opening angle, and the exhaust valve target closing angle; Determine the intake valve second opening angle comparison value, the intake valve second closing angle comparison value, the exhaust valve second opening angle comparison value and the exhaust valve second closing angle comparison value based on the second reference signal, the intake valve target opening angle, the intake valve target closing angle, the exhaust valve target opening angle and the exhaust valve target closing angle.

6. The control method according to claim 4, characterized in that: Determining the opening and closing times of the valve according to the opening and closing angle comparison value and the opening and closing time comparison value includes: Determining an opening time of an intake valve and an opening time of an exhaust valve according to the first intake valve opening angle comparison value, the first exhaust valve opening angle comparison value, the second intake valve opening angle comparison value, the second exhaust valve opening angle comparison value, the first intake valve opening time comparison value, and the first exhaust valve opening time comparison value; The closing timing of the intake valve and the closing timing of the exhaust valve are determined based on the intake valve first closing angle comparison value, the exhaust valve first closing angle comparison value, the intake valve second closing angle comparison value, the exhaust valve second closing angle comparison value, the intake valve first closing time comparison value and the exhaust valve first closing time comparison value.

7. The control method according to claim 6, characterized in that: Determining the opening timing of the intake valve and the opening timing of the exhaust valve according to the first intake valve opening angle comparison value, the first exhaust valve opening angle comparison value, the second intake valve opening angle comparison value, the second exhaust valve opening angle comparison value, the first intake valve opening time comparison value, and the first exhaust valve opening time comparison value, including: When the first opening angle comparison value of the intake valve and the first opening angle comparison value of the exhaust valve both meet the first preset opening angle condition, and the second opening angle comparison value of the intake valve and the second opening angle comparison value of the exhaust valve both meet the second preset opening angle condition, controlling the output of an opening pulse to open the intake valve and the exhaust valve; When the intake valve and / or the exhaust valve is not opened, based on the intake valve first opening time comparison value and / or the exhaust valve first opening time comparison value, when the intake valve first opening time comparison value satisfies the first preset opening time condition, and / or the exhaust valve first opening time comparison value satisfies the second preset opening time condition, the opening pulse is controlled to be output to open the intake valve and / or the exhaust valve.

8. The control method according to claim 6, characterized in that: Determining the closing time of the intake valve and the closing time of the exhaust valve according to the first intake valve closing angle comparison value, the first exhaust valve closing angle comparison value, the second intake valve closing angle comparison value, the second exhaust valve closing angle comparison value, the first intake valve closing time comparison value, and the first exhaust valve closing time comparison value, comprises: When the first closing angle comparison value of the intake valve and the first closing angle comparison value of the exhaust valve both meet the first preset closing angle condition, or when the second closing angle comparison value of the intake valve and the second closing angle comparison value of the exhaust valve both meet the second preset closing angle condition, controlling the output of a closing pulse to close the intake valve and the exhaust valve; When the intake valve and / or the exhaust valve are not closed, based on the intake valve first closing time comparison value and / or the exhaust valve first closing time comparison value, when the intake valve first closing time comparison value meets the first preset closing time condition, and / or the exhaust valve first closing time comparison value meets the second preset closing time condition, the closing pulse is controlled to be output to close the intake valve and / or the exhaust valve.

9. The control method according to claim 1, characterized in that: Before acquiring the first reference signal and the second reference signal, the method further includes: The first reference signal and the second reference signal are subjected to cylinder judgment and self-calibration to determine the signal states of the first reference signal and the second reference signal.

10. An engine system, characterized in that: A control method for a fully variable valve is used to implement any one of claims 1-9.

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