A fully variable valve control method and engine system

Abstract

The present invention discloses a fully variable valve control method and engine system, the method comprising: obtaining a first reference signal, a second reference signal, and a current operating condition signal of the engine during engine operation; determining a target opening angle and a target closing angle of the valve based on the current operating condition signal; determining the opening and closing times of the valve based on the current operating condition signal, the first reference signal, the second reference signal, the target opening angle, and the target closing angle; obtaining the actual opening angle when the valve is open, and obtaining the actual closing angle when the valve is closed; and performing real-time corrections on the target opening angle and the target closing angle 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, 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. Using the above method, precise control of 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 for a fully variable valve and an engine system. Background Art

[0002] An engine's valves are typically driven by a camshaft. For conventional engines without variable valve timing, the opening and closing times of the intake and exhaust valves are fixed. However, this fixed valve timing makes it difficult to adapt to varying engine speeds and operating conditions. To address this, fully variable valve timing has been increasingly adopted in recent years to improve engine power, fuel economy, and reduce emissions. Fully variable valve timing systems flexibly control the valve opening and closing angles based on the engine's varying operating requirements by controlling the solenoid valve's energization and de-energization times. However, the solenoid valve's energization and de-energization times are controlled based on a crankshaft signal. Any erroneous crankshaft signal can lead to a deviation in the actuation timing, resulting in inaccurate valve opening and closing angles, potentially leading to serious accidents such as piston impact on the valve.

[0003] Existing valve control typically calibrates the target angle based on the delay between the actual opening and closing angles, assuming a correct drive reference signal. This correction is then compared with the maximum delay to determine if an error exists. However, this method suffers from a delay in judgment, making it impossible to prevent piston impact on the valve after a serious fault, impacting 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 engine system, which utilizes angle closed-loop control to achieve precise control of the valve opening and closing angles, 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 fully variable valve control method for use in an engine system, the system comprising 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 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] 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;

[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, as well as 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 valve opening angle and target valve closing angle based on the current operating 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, exhaust valve target opening angle, intake valve target closing angle and exhaust valve target closing angle are determined respectively.

[0015] Optionally, determining the valve opening and closing times 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 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;

[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] determining 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 based on the first reference signal, the second reference signal, the target opening angle, and the target closing angle;

[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 a target opening angle of the intake valve and a target opening angle of the exhaust valve, and the target closing angle includes a target closing angle of the intake valve and a target closing angle of the exhaust valve;

[0023] Determining 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 based on the first reference signal, the second reference signal, the target opening angle, and the target closing angle, including:

[0024] determining a first intake valve opening angle comparison value, a first intake valve closing angle comparison value, a first exhaust valve opening angle comparison value, and a first exhaust valve closing angle comparison value based on 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;

[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 an opening timing of the intake valve and an 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;

[0028] The closing time of the intake valve and the closing time of the exhaust valve are determined based on 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.

[0029] Optionally, 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 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 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 second preset opening angle condition, controlling the output of an opening pulse to open the intake valve and the exhaust valve;

[0031] When the intake valve and / or exhaust valve are not open, based on the first opening time comparison value of the intake valve and / or the first opening time comparison value of the exhaust valve, when the first opening time comparison value of the intake valve meets the first preset opening time condition, and / or the first opening time comparison value of the exhaust valve 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 timing of the intake valve and the closing timing 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 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, based on the first closing time comparison value of the intake valve and / or the first closing time comparison value of the exhaust valve, when the first closing time comparison value of the intake valve meets the first preset closing time condition, and / or the first closing time comparison value of the exhaust valve 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 obtaining 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-calibration 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 a first reference signal, a second reference signal, and a current operating condition signal of the engine during the operation of the engine; determine the target opening angle and target closing angle of the valve according to the current operating condition signal; determine 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; 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; and make real-time corrections to the target opening angle and the target closing angle 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, 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, angle closed-loop control is used to achieve precise control of the valve opening angle and closing angle, thereby avoiding the phenomenon of piston hitting the valve, improving the performance and reliability of the engine system, and extending the service life of the engine system.

[0039] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily 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 diagram of a first reference signal provided by an embodiment of the present invention;

[0043] Figure 3 A signal 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 solutions of the present invention, the technical solutions 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 embodiments described 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 making creative efforts should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "first", "second", etc. in the description 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 numbers 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 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 This is a flow chart of a fully variable valve control method provided by an embodiment of the present invention. Figure 2 A signal 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 output of the opening and closing angles of the valves to avoid the phenomenon of piston hitting the valves. This method can be executed by a fully variable valve control device, which 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 is 180° different 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 a first reference signal Ne1 and a 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 engine operation, obtain a first reference signal, a second reference signal, and a current operating condition signal of the engine.

[0050] The current operating condition signal of the engine may include, but is not limited to, engine speed, engine fuel injection amount, and instantaneous acceleration of the engine, etc. The specific conditions may be determined according to actual conditions 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 obtained, and the current operating condition signal of the engine is obtained at the same time. The current operating condition signal can be obtained based on but not limited to obtaining it through the corresponding sensor.

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

[0053] Specifically, after obtaining the current engine operating condition signal, a target valve opening angle and a target valve closing angle can be determined based on the current engine operating condition using a preset correspondence. Typically, valves include intake and exhaust valves, and the target valve opening and closing angles include those for the intake and exhaust valves, respectively. Furthermore, the target valve opening and closing angles calculated in this step are the desired valve angle targets.

[0054] S130 , 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.

[0055] The valve opening time is the scheduled opening time, i.e., the time at which the valve is expected to open. Similarly, the valve closing time is the scheduled closing time, i.e., the time at which the valve is expected to close. In this embodiment, to ensure system safety, the valve cannot be opened prematurely, but can be closed prematurely.

[0056] Specifically, after determining the target opening angle and target closing angle of the outlet valve, a comparison value for the outlet valve opening and closing angles can be determined based on the first reference signal, the second reference signal, and the target opening and closing angles of the valve. A comparison value for the outlet valve opening and closing time can be determined based on the current operating condition signal and the target opening and closing angles of the valve. After determining the opening and closing angle comparison values ​​and the opening and closing time comparison values, the outlet valve opening and closing times can be determined based on preset logical judgments.

[0057] S140: 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.

[0058] The actual valve opening angle is the angle at which the valve is actually opened when the valve is opened, and the actual valve closing angle is the angle at which the valve is actually closed when the valve is closed. The actual valve opening angle and the actual valve closing angle can be obtained, including but not limited to, through a valve position sensor, which is not limited here.

[0059] Specifically, after determining the valve opening moment, the intake valve or exhaust valve is controlled to open to the corresponding target opening angle. However, due to certain reasons, a certain degree of angle error is inevitably generated during the actual opening process, causing the actual opening angle of the intake valve or exhaust valve to differ from the target opening angle. Therefore, to determine the actual opening angle, the actual opening angle of the intake valve or exhaust valve can be obtained after the intake valve or exhaust valve is opened. For example, the target opening angle is 10°, and the actual opening angle obtained is 8°. Similarly, after determining the valve closing moment, the intake valve or exhaust valve is controlled to close from the target opening angle. However, due to certain reasons, a certain degree of angle error is inevitably generated during the actual closing process, causing the actual closing angle of the intake valve or exhaust valve to differ from the target closing angle. Therefore, to determine the actual closing angle, the actual closing angle of the intake valve or exhaust valve can be obtained after the intake valve or exhaust valve is closed. For example, the target closing angle is 10°, and the actual closing angle obtained is 8°, indicating that the valve is not fully 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 valve opening angle and actual closing angle, it is necessary to perform real-time corrections to the target opening angle and target closing angle 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°. During the next engine cycle, the target opening angle is 8°. After the target opening angle is corrected, the corresponding valve opening time and 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, indicating that the real-time correction process is completed, and 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, which can be referred to as the target opening angle and will not be described in detail here. The closed-loop control logic improves the control accuracy of the valve opening and closing angles.

[0062] The technical solution of the embodiment of the present invention is to obtain a first reference signal, a second reference signal, and a current operating condition signal of the engine during the operation of the engine; determine the target opening angle and target closing angle of the valve according to the current operating condition signal; determine 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; 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; and make real-time corrections to the target opening angle and the target closing angle 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, 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, angle closed-loop control is used to achieve precise control of the valve opening angle and closing angle, thereby avoiding the phenomenon of piston hitting the valve, improving the performance and reliability of the engine system, and extending the service life of the engine system.

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

[0064] S210 , performing cylinder identification 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] Cylinder determination is the process of determining the precise position of each engine cylinder during engine operation through the combined efforts of the crankshaft position sensor and camshaft position sensor. The crankshaft position sensor detects one or more missing teeth on the crankshaft signal disk, corresponding to the top dead center position of a specific cylinder. When the crankshaft position sensor detects a missing tooth signal, it indicates that it has identified a specific position on the crankshaft signal disk, typically a specific angle before top dead center of the first or fourth cylinder, indicating that 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 profile of 60-2, that is, there are 58 normal teeth and 1 missing tooth in one rotation of the crankshaft, and 1 missing tooth includes two normal teeth. The engine works 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, namely 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 determined that the cylinder is completed. At this time, the angle of the first normal tooth after the first missing tooth 31 is used 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, 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. If 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 confirmed during the self-calibration process. When it is determined that one 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 process of the second reference signal Ne2 is the same as that of the first reference signal Ne1. Please refer to the self-calibration process of the first reference signal Ne1 and will not be repeated here.

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

[0068] The current operating condition signal includes an engine speed signal, a target fuel injection quantity signal, and an engine instantaneous acceleration signal. The engine speed signal may be obtained, but is not limited to, via a speed sensor, or may be determined based on normal teeth and missing teeth in the first reference signal and the second reference signal. The target fuel injection quantity signal may be determined and obtained based on the engine speed using a preset correspondence between the engine speed and the target fuel injection quantity. The engine instantaneous acceleration signal may be obtained, but is not limited to, via an acceleration sensor.

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

[0070] Specifically, after acquiring the engine speed signal and the target fuel injection quantity signal, a first preset correspondence relationship is used to determine the correspondence between the engine speed signal, the target fuel injection quantity signal, and the target intake valve opening angle. After the engine speed signal and the target fuel injection quantity signal are determined and input into the first preset correspondence relationship, the corresponding target intake valve opening angle can be determined. Similarly, based on a second preset correspondence relationship, the second preset correspondence relationship is used to determine the correspondence between the engine speed signal, the target fuel injection quantity signal, and the target exhaust valve opening angle, the engine speed signal and the target fuel injection quantity signal can be input into the second preset correspondence relationship to determine the corresponding target exhaust valve opening angle. Based on a third preset correspondence relationship, the third preset correspondence relationship is used to determine the correspondence between the engine speed signal, the target fuel injection quantity signal, and the target intake valve closing angle, the engine speed signal and the target fuel injection quantity signal can be input into the third preset correspondence relationship to determine the corresponding target intake valve closing angle. Based on a fourth preset correspondence relationship, the fourth preset correspondence relationship is used to determine the correspondence between the engine speed signal, the target fuel injection quantity signal, and the target exhaust valve closing angle. The engine speed signal and the target fuel injection quantity signal may be input into a fourth preset correspondence to determine a corresponding exhaust valve target closing angle.

[0071] S213 . Determine a valve opening and closing angle comparison value and a 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 as follows: according to the first reference signal, the second reference signal, the target opening angle and the target closing angle, determine 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; according to the engine speed signal, the engine instantaneous acceleration signal, the target opening angle and the target closing angle, 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.

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

[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 target opening angles and target closing angles, namely, 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 actual positions of the normal and missing teeth can be determined based on the first reference signal, and a comparator value is associated with each tooth position. Typically, when a tooth is displayed on the comparator, the tooth signal is divided into 100 parts. For example, the comparator value corresponding to the first tooth is 100, the comparator value corresponding to the second tooth is 200, and so on. Based on 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 predetermined correspondence with a tooth. Therefore, based on the target opening angle and target closing angle, the corresponding tooth position can be determined. Furthermore, based on the tooth position, the comparator value corresponding to the tooth position can be determined, 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 intake valve first opening time comparison value 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 two teeth are required. These two teeth will be converted into the comparator value, which is 200. Therefore, the comparator value 200 is the determined intake valve first opening time comparison value, 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 second reference signal can be combined with the target opening angle and target closing angle, namely, 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 actual positions of the normal and missing teeth can be determined based on the second reference signal, and each tooth position corresponds to a comparator value. Typically, when a tooth is displayed on the comparator, the tooth signal is divided into 100 parts. For example, the comparator value corresponding to the first tooth is 100, the comparator value corresponding to the second tooth is 200, and so on. In this case, based on 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 corresponds to a tooth. Therefore, based on the target opening angle and target closing angle, the corresponding tooth position can be determined. Furthermore, based on the tooth position, the comparator value corresponding to the tooth position can be determined, 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 this embodiment, based on 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 tooth, and there is also a preset corresponding relationship between 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 tooth position. The tooth position also has a corresponding relationship with the value of the comparator. Therefore, the tooth position is used as a conversion medium to finally determine the first intake valve opening time comparison value, the first intake valve closing time comparison value, the first exhaust valve opening time comparison value and the first exhaust valve closing time comparison value.

[0078] S214: Determine 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.

[0079] Among them, this step can be further refined as follows: determining the opening time of the intake valve and the opening time of the exhaust valve based on 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 based on 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 valve opening and closing times. In this embodiment, the intake valve opening and exhaust valve opening times can be determined based on the intake valve first opening angle comparison value and the exhaust valve first opening angle comparison value. When both the intake valve first opening angle comparison value and the exhaust valve first opening angle comparison value satisfy corresponding first preset opening angle conditions, the first preset opening angle conditions being that the intake valve first opening angle comparison value and the exhaust valve first opening angle comparison value are the same as the angle corresponding to the teeth of the crankshaft signal disk that continuously rotates in the first timer, and the exhaust valve first opening angle comparison value and the exhaust valve first opening angle comparison value are the same as the angle corresponding to the teeth of the crankshaft signal disk that continuously rotates in the first timer, indicating that the signal outputs of the intake valve first opening angle comparison value and the exhaust valve first opening angle comparison value are normal. 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 outputting an opening pulse, 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 counted time reaches the preset opening time, the intake valve and / or exhaust valve has not yet 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 open; 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 at this time, and it only exists as a protection logic and 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 have a certain time lag than the output opening angle pulse.Specifically, when the intake valve is not open, based on the first intake valve opening time comparison value, if the first intake valve opening time comparison value satisfies a first preset opening time condition, i.e., reaches the preset opening time corresponding to intake valve opening, indicating that the intake valve has reached its opening time, a high-level opening pulse is triggered to control the intake valve opening. When the exhaust valve is not open, based on the first exhaust valve opening time comparison value, if the first exhaust valve opening time comparison value satisfies a second preset opening time condition, i.e., reaches the preset opening time corresponding to exhaust valve opening, indicating that the exhaust valve has reached its opening time, a high-level opening pulse is triggered to control the exhaust valve opening. This ensures that the intake and exhaust valves do not open abnormally early.

[0081] It should be noted that while the above embodiment describes the determination of both the intake and exhaust valve opening times, in practice, when controlling intake valve opening, only the relationships between the first intake valve opening angle comparison value, the second intake valve opening angle comparison value, and the first intake valve opening time comparison value, and their corresponding preset conditions, are considered. When the first intake valve opening angle comparison value satisfies the first preset opening angle condition and the second intake valve opening angle comparison value satisfies the second preset opening angle condition, the intake valve is controlled to open. If the intake valve still does not open after the output opening pulse has elapsed for the preset opening time, the intake valve is controlled to open based on the first intake valve opening time comparison value when the first intake valve opening time comparison value reaches the first preset opening time condition. Similarly, when controlling exhaust valve opening, only the relationships between the first exhaust valve opening angle comparison value, the second exhaust valve opening angle comparison value, and the first exhaust valve opening time comparison value, and their corresponding preset conditions, are considered. When the first exhaust valve opening angle comparison value satisfies the first preset opening angle condition and the second exhaust valve opening angle comparison value satisfies the second preset opening angle condition, the exhaust valve is 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 first exhaust valve opening time comparison value. When the first exhaust valve opening time comparison value reaches the second preset opening time condition, the exhaust valve is controlled to open.

[0082] Furthermore, when determining the closing timing of the intake valve, if the first closing angle comparison value of the intake valve satisfies a first preset closing angle condition (the first preset closing angle condition being the same as the angle corresponding to the tooth of the crankshaft signal disk that rotates continuously during the first timer), or if the second closing angle comparison value of the intake valve satisfies a second preset closing angle condition (the second preset opening angle condition being the same as the angle corresponding to the tooth of the crankshaft signal disk that rotates continuously during the first timer), that is, if the "OR" logical condition is satisfied, the intake valve has reached the closing condition. At this point, a closing pulse can be output to close the intake valve. If the intake valve has not closed within the preset closing time after the output of the closing pulse, the first closing time comparison value is used to control the intake valve closing, ensuring timely closing of the intake valve. If the intake valve has completely closed within the preset closing time after the output of the closing pulse, the first closing time comparison value is ignored. In this case, the first closing angle comparison value serves only as a protection logic and does not affect intake valve closing. In this case, the closing time pulse output by the intake valve lags behind 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 exhaust valve closing timing, if the exhaust valve first closing angle comparison value satisfies a first preset closing angle condition (the first preset opening angle condition being the same as the angle corresponding to the tooth of the crankshaft signal disk that has been cyclically rotating during the first timer), or if the exhaust valve second closing angle comparison value satisfies a second preset closing angle condition (the second preset opening angle condition being the same as the angle corresponding to the tooth of the crankshaft signal disk that has been cyclically rotating during the first timer), the exhaust valve has reached the closing condition. At this point, a closing pulse can be output to close the exhaust valve. If the exhaust valve has not closed within the preset closing time from the output of the closing pulse, the exhaust valve is closed based on the first closing time comparison value to ensure timely closing of the exhaust valve. If the exhaust valve has completely closed within the preset closing time from the output of the closing pulse, the first closing time comparison value is ignored. In this case, the first closing angle comparison value serves only as a protection logic and does not affect exhaust valve closing. That is, the closing time pulse output by the exhaust valve lags behind the closing angle pulse. If the exhaust valve does not close within the preset closing time, the control outputs a closing pulse to close the exhaust valve based on the exhaust valve first closing time comparison value. If the exhaust valve first closing time comparison value satisfies the first preset closing time condition, which is the preset closing time corresponding to the exhaust valve closing, indicating that the latest closing time of the exhaust valve has been reached, the control outputs a closing pulse to close the exhaust valve. This ensures that the intake and exhaust valves do not close abnormally late.

[0084] Furthermore, if an anomaly occurs in either the first or second reference signals—for example, if the first reference signal completes cylinder determination but the second reference signal does not—then the abnormal second reference signal is diagnosed. In this case, the abnormal second reference signal may be triggered prematurely, but the normal first reference signal has not yet been triggered. In this case, after receiving the first and second reference signals, the intake and exhaust valves will not be controlled for opening. Instead, the valves will be controlled based on the intake and exhaust valve first opening time comparison values. However, the valves can be closed prematurely. Therefore, even if the second reference signal triggers abnormally early, i.e., opens and closes earlier than the first reference signal, the valves can still be controlled for closing. In this case, the intake and exhaust valve first closing time comparison values ​​will be ignored. Furthermore, while controlling the opening and closing of the intake and exhaust valves, the faulty or abnormal second reference signal is monitored and reported to ensure prompt investigation of the cause of the anomaly.

[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 early 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 when there is signal lag in both the first reference signal and the second reference signal, the opening and closing angle comparison values ​​are unreliable. Then, 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 and 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 and second reference signals by performing cylinder judgment and self-calibration on the first and second reference signals; 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 based on different preset corresponding relationships according to the engine speed signal and the target fuel injection quantity signal; determines the valve opening and closing angle comparison value and the 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; and determines the valve opening and closing time according to the opening and closing angle comparison value and the opening and closing time comparison value. Utilizing the above method, according to the preset control logic, precise control of the opening and closing time of the intake and exhaust valves is achieved, ensuring that the intake and exhaust valves will not open prematurely but can close prematurely, thereby improving the safety and reliability of the engine system and extending 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, which has corresponding functional modules and beneficial effects of the execution method.

[0091] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0092] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A fully variable valve control method, characterized in that: Applied to an engine system, the 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; the first crankshaft position sensor and the second crankshaft position sensor are located on opposite sides of the crankshaft signal disk, respectively, to detect the angular displacement of the crankshaft signal disk when the crankshaft signal disk rotates, and generate a first reference signal and a second reference signal, respectively; The method is executed by the control unit, and the method includes: During engine operation, obtaining 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 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; 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; Wherein, 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 includes: determining 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 and closing times of the valve are determined based on the opening and closing angle comparison value and the opening and closing time comparison value; the opening and closing angle comparison value is set in a comparator or a timer to convert the target opening angle and the target closing angle into numerical values ​​input into the comparator or the timer for comparison; the opening and closing time comparison value is a time value calculated based on the engine speed, instantaneous acceleration, the target opening angle and 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; 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 2, 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 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 includes: determining the first intake valve opening angle comparison value, the first intake valve closing angle comparison value, the first exhaust valve opening angle comparison value, the first exhaust valve closing angle comparison value, the second intake valve opening angle comparison value, the second intake valve closing angle comparison value, the second exhaust valve opening angle comparison value, and the second exhaust valve closing angle comparison value based on 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 based on the engine speed signal, the engine instantaneous acceleration signal, the target opening angle and the target closing angle.

4. The control method according to claim 3, characterized in that: 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; Determining the first intake valve opening angle comparison value, the first intake valve closing angle comparison value, the first exhaust valve opening angle comparison value, the first exhaust valve closing angle comparison value, the second intake valve opening angle comparison value, the second intake valve closing angle comparison value, the second exhaust valve opening angle comparison value, and the second exhaust valve closing angle comparison value based on the first reference signal, the second reference signal, the target opening angle, and the target closing angle includes: 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 based on 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; 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.

5. The control method according to claim 3, 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 timing of the intake valve and an 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; The closing timing of the intake valve and the closing timing of the exhaust valve are determined based on 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.

6. The control method according to claim 5, 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 includes: When the first intake valve opening angle comparison value and the first exhaust valve opening angle comparison value both meet a first preset opening angle condition, and when the second intake valve opening angle comparison value and the second exhaust valve opening angle comparison value both meet a 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 are not open, 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 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 opening pulse is controlled to be output to open the intake valve and / or the exhaust valve.

7. The control method according to claim 5, characterized in that: Determining the closing timing of the intake valve and the closing timing 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 includes: When the first closing angle comparison value of the intake valve and the first closing angle comparison value of the exhaust valve both meet a 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 a 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.

8. 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.

9. An engine system, characterized in that: A control method for a fully variable valve according to any one of claims 1 to 8.

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