Needle valve seating bounce driving control method for injector of in-cylinder hydrogen direct injection engine

Abstract

The invention discloses a needle valve seating bounce driving control method for an injector of a direct-injection hydrogen engine, which comprises the following steps of: S1, constructing a three-order current driving model by a controller, the magnitude and duration time of main pull-up current used for controlling the electromagnetic valve of the hydrogen ejector to be completely opened and the magnitude and duration time of auxiliary pull-up current used for reducing the vibration jump amplitude generated when the electromagnetic valve of the hydrogen ejector is opened are defined. And a magnitude and duration of a buffer current for reducing a vibration jump amplitude generated when the hydrogen injector solenoid valve is closed; and S2, the controller controls a PWM module according to the definition in the three-order current driving model, so that current is provided for an electromagnetic coil of the electromagnetic valve of the hydrogen ejector, and the vibration jump problem of the electromagnetic valve of the hydrogen ejector is solved. The collision problem generated in the opening process and the collision problem generated in the seating process are effectively solved, and the explosion danger caused by hydrogen leakage is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogen engine injectors, and in particular relates to a needle valve seating rebound drive control method of an in-cylinder direct injection hydrogen engine injector. Background Art

[0002] With the rapid development of Chinese society and the continuous improvement of people's living standards, environmental issues have become a major issue that people are increasingly concerned about. Hydrogen has the advantages of high calorific value, zero emissions, and easy access. Therefore, it has become the main alternative fuel to chemical fuels, and thus developed hydrogen fuel cells, hydrogen internal combustion engines and other equipment that use hydrogen as the main fuel.

[0003] Although the efficiency of hydrogen fuel cells is slightly higher than that of hydrogen internal combustion engines, their performance at high power is weaker than that of hydrogen internal combustion engines. This is because hydrogen fuel cells need to rely heavily on the diffusion speed of fuel when working. In addition, hydrogen fuel cells also have high requirements for the purity of hydrogen, which increases the cost. There are two main working modes for the fuel supply of hydrogen internal combustion engines: hydrogen injection through the intake port and direct injection of hydrogen into the cylinder. When hydrogen is injected through the intake port, due to the low density of hydrogen and the large volume of hydrogen for a certain mass, it will occupy the volume of fresh air during the intake process, affecting the intake efficiency and the power output of the engine. Studies have shown that the power output of the intake port injection hydrogen engine of the same speed and size is lower than that of the gasoline engine. At the same time, backfire is also a problem to be solved by the intake port hydrogen injection engine. In addition, the extinguishing distance of hydrogen is small, and the flame of hydrogen combustion is more difficult to extinguish than other fuels. The flame will pass through the nearly closed intake valve and cause the backfire problem. The current solution to the backfire problem is to use high-pressure direct injection technology in the cylinder. Therefore, in order to improve the power and thermal efficiency of hydrogen engines and avoid the occurrence of backfire problems, hydrogen engines using high-pressure direct injection in the cylinder are the current research focus of hydrogen engines. For high-pressure direct injection hydrogen engines, the hydrogen injector is one of the key components of the high-pressure direct injection hydrogen engine. In order to make the hydrogen injector work more efficiently and accurately, it is necessary to study and analyze the electromagnetic drive characteristics of the hydrogen injector, clarify the functions and performance requirements of the hydrogen injector controller, and achieve precise hydrogen injection control to improve the power and economy of hydrogen fuel vehicles and reduce emissions.

[0004] Up to now, hydrogen internal combustion engines have a history of several decades of development. For hydrogen internal combustion engines, the hydrogen injector is one of the most important components, and its performance and control have a great impact on the power output and power of the hydrogen engine.

[0005] In order to meet the performance requirements of the injector of the direct injection hydrogen engine, the jump problem of the start and close of the hydrogen injector is optimized to prevent the influence of the jump problem of the hydrogen injector solenoid valve in the open state and the closed state. Since the lubricity and viscosity of hydrogen are much lower than those of liquid fuels, namely gasoline and diesel, the damping force that the hydrogen injector will be subjected to during operation is also smaller than that of liquid fuel. In particular, when the needle valve of the hydrogen injector falls back, it will cause excessive mechanical impact between the needle valve and the outer cover, affecting the life of the hydrogen injector. At the same time, it will also cause the risk of the hydrogen injector failing to close on time and opening by mistake.

[0006] Therefore, it is very important to solve the problem of needle valve rebound. To this end, research on the drive and control technology of hydrogen injectors and a series of key technology research are of great significance both in engineering application and theoretical value. In the prior art, many people have also studied the drive and control technology of hydrogen injectors, but there is still a lack of effective methods for how to realize the drive control of the needle valve seat rebound of the hydrogen engine injector. Once the rebound causes hydrogen leakage, it will cause the risk of explosion. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a needle valve seating rebound drive control method for an in-cylinder direct injection hydrogen engine injector in view of the deficiencies in the above-mentioned prior art, which can effectively reduce the collision problems generated during opening and the collision problems generated during seating, and avoid the risk of explosion caused by hydrogen leakage.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is: a needle valve seating rebound drive control method of an in-cylinder direct injection hydrogen engine injector, the control system adopted by the present invention comprises a controller, a PWM module, a buck-boost chopper circuit, a MOS tube and a current sampling module, the controller, the PWM module, the buck-boost chopper circuit and the MOS tube are connected in sequence, the MOS tube is connected to the electromagnetic coil of the hydrogen injector solenoid valve, and the current sampling module is respectively connected to the electromagnetic coil of the hydrogen injector solenoid valve and the controller; the needle valve seating rebound drive control method comprises the following steps:

[0009] Step S1, the controller constructs a third-order current drive model, in which the third-order current drive model defines the magnitude and duration of a main pull-up current for controlling the full opening of the hydrogen injector solenoid valve, the magnitude and duration of a secondary pull-up current for reducing the vibration jump amplitude generated when the hydrogen injector solenoid valve is opened, and the magnitude and duration of a buffer current for reducing the vibration jump amplitude generated when the hydrogen injector solenoid valve is closed;

[0010] Step S2, the controller controls the PWM module to output three PWM pulse signals with a duty cycle of α1 and a period of T1, a duty cycle of α2 and a period of T2, and a duty cycle of α3 and a period of T3 to the MOS tube in sequence according to the main pull-up current size and duration, the auxiliary pull-up current size and duration, and the buffer current size and duration defined in the third-order current drive model, and then transmits them to the electromagnetic coil of the hydrogen injector solenoid valve, and provides the main pull-up current to the electromagnetic coil of the hydrogen injector solenoid valve through the PWM pulse signal with a duty cycle of α1 and a period of T1, and provides the auxiliary pull-up current to the electromagnetic coil of the hydrogen injector solenoid valve through the PWM pulse signal with a duty cycle of α2 and a period of T2, so as to reduce the vibration jump problem generated when the hydrogen injector solenoid valve is opened; and provides the buffer current to the electromagnetic coil of the hydrogen injector solenoid valve through the PWM pulse signal with a duty cycle of α3 and a period of T2, so as to reduce the vibration jump problem generated when the hydrogen injector solenoid valve is closed; wherein, α1>α2>α3;

[0011] During the execution of step S2, the current sampling module samples the current of the electromagnetic coil and outputs the sampled current signal to the controller. The controller adjusts the output duty cycle of the PWM module according to the sampled current signal to make the output current as close as possible to the main pull-up current, auxiliary pull-up current or buffer current defined in the third-order current drive model.

[0012] The above-mentioned needle valve seating bounce drive control method of the direct injection hydrogen engine injector is characterized in that: the controller constructs a third-order current drive model using a method combining simulation with experimental testing and expert system, and constructs a function αi=A1α based on the duty cycle multi-parameter model 1i +A2α 2i +A3α 3i Calculate the duty cycle α1, duty cycle α2, and duty cycle α3, and construct the function Ti=B1T based on the periodic multi-parameter model 1i +B2T 2i +B3T 3i Calculate the size of period T1, period T2, and period T3; where i is 1, 2, or 3, α 1i is the size of duty cycle α1, duty cycle α2 or duty cycle α3 determined by simulation method, α 2i is the size of duty cycle α1, duty cycle α2 or duty cycle α3 determined by experimental test method, α 3i is the size of duty cycle α1, duty cycle α2 or duty cycle α3 determined by the expert system method, A1 is α 1i The weight coefficient of A2 is α 2i The weight coefficient of A3 is α 3i The weight coefficient of 1iis the size of period T1, period T2, and period T3 determined by simulation method, T 2i is the size of period T1, period T2, and period T3 determined by simulation method, T 3i is the size of period T1, period T2, and period T3 determined by the expert system method, B1 is α 1i The weight coefficient of B2 is α 2i The weight coefficient of B3 is α 3i The weight coefficient of .

[0013] In the above-mentioned needle valve seating bounce drive control method of the in-cylinder direct injection hydrogen engine injector, A1, A2, A3, and B1, B2, B3 are weight coefficients determined by training based on a large amount of historical data through a reinforcement learning algorithm.

[0014] The above-mentioned needle valve seating bounce drive control method of the in-cylinder direct injection hydrogen engine injector, the simulation method is a Simulink simulation method.

[0015] In the above-mentioned needle valve seating bounce drive control method for the injector of a direct-injection hydrogen engine, the controller in step S2 adjusts the output duty cycle of the PWM module according to the sampled current signal to make the output current size as close as possible to the main pull-up current size, the auxiliary pull-up current size or the buffer current size defined in the third-order current drive model, and an improved PID controller model is used for implementation. In the improved PID controller model, a low-pass filter is introduced in the differential link of the conventional PID to solve the high-frequency interference introduced by the differential regulation and reduce the instability caused by the sudden change of error disturbance.

[0016] The above-mentioned needle valve seating rebound drive control method of the direct injection hydrogen engine injector is characterized in that: the energy storage inductor in the step-up and step-down chopper circuit is selected according to the formula Where, R is the load resistance, αi is the duty cycle α1, duty cycle α2 or duty cycle α3, and f is the switching frequency of the MOS tube.

[0017] The above-mentioned needle valve seating bounce drive control method of the in-cylinder direct injection hydrogen engine injector is characterized in that: the controller is an ARM controller.

[0018] Compared with the prior art, the present invention has the following advantages: the present invention not only proposes a method for controlling the seating bounce drive of the needle valve of the injector of a direct injection hydrogen engine using a third-order current drive model, but also proposes a method for how to achieve precise control of the third-order current in the third-order current drive model. The third-order current drive model is constructed by combining simulation with experimental testing and an expert system, and an improved PID controller model is used to control the output current to better match the preset current, which can effectively improve the control accuracy, effectively reduce the collision problem generated during opening and the collision problem generated during seating, and avoid the risk of explosion caused by hydrogen leakage.

[0019] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flowchart of the method of the present invention;

[0021] Figure 2 The schematic diagram of the control system used in the present invention;

[0022] Figure 3 It is a circuit principle diagram of the buck-boost chopper circuit of the present invention. DETAILED DESCRIPTION

[0023] like Figure 1 and Figure 2 As shown, the needle valve seating rebound drive control method of the in-cylinder direct injection hydrogen engine injector of the present invention adopts a control system comprising a controller, a PWM module, a buck-boost chopper circuit, a MOS tube and a current sampling module, wherein the controller, the PWM module, the buck-boost chopper circuit and the MOS tube are connected in sequence, the MOS tube is connected to the electromagnetic coil of the hydrogen injector solenoid valve, and the current sampling module is respectively connected to the electromagnetic coil of the hydrogen injector solenoid valve and the controller; the needle valve seating rebound drive control method comprises the following steps:

[0024] Step S1, the controller constructs a third-order current drive model, in which the third-order current drive model defines the magnitude and duration of a main pull-up current for controlling the full opening of the hydrogen injector solenoid valve, the magnitude and duration of a secondary pull-up current for reducing the vibration jump amplitude generated when the hydrogen injector solenoid valve is opened, and the magnitude and duration of a buffer current for reducing the vibration jump amplitude generated when the hydrogen injector solenoid valve is closed;

[0025] Step S2, the controller controls the PWM module to output three PWM pulse signals with a duty cycle of α1 and a period of T1, a duty cycle of α2 and a period of T2, and a duty cycle of α3 and a period of T3 to the MOS tube in sequence according to the main pull-up current size and duration, the auxiliary pull-up current size and duration, and the buffer current size and duration defined in the third-order current drive model, and then transmits them to the electromagnetic coil of the hydrogen injector solenoid valve, and provides the main pull-up current to the electromagnetic coil of the hydrogen injector solenoid valve through the PWM pulse signal with a duty cycle of α1 and a period of T1, and provides the auxiliary pull-up current to the electromagnetic coil of the hydrogen injector solenoid valve through the PWM pulse signal with a duty cycle of α2 and a period of T2, so as to reduce the vibration jump problem generated when the hydrogen injector solenoid valve is opened; and provides the buffer current to the electromagnetic coil of the hydrogen injector solenoid valve through the PWM pulse signal with a duty cycle of α3 and a period of T2, so as to reduce the vibration jump problem generated when the hydrogen injector solenoid valve is closed; wherein, α1>α2>α3;

[0026] During the execution of step S2, the current sampling module samples the current of the electromagnetic coil and outputs the sampled current signal to the controller. The controller adjusts the output duty cycle of the PWM module according to the sampled current signal to make the output current as close as possible to the main pull-up current, auxiliary pull-up current or buffer current defined in the third-order current drive model.

[0027] In this embodiment, the controller constructs a third-order current drive model by combining simulation with experimental testing and expert system, and constructs a function αi=A1α according to the duty cycle multi-parameter model. 1i +A2α 2i +A3α 3i Calculate the duty cycle α1, duty cycle α2, and duty cycle α3, and construct the function Ti=B1T based on the periodic multi-parameter model 1i +B2T 2i +B3T 3i Calculate the size of period T1, period T2, and period T3; where i is 1, 2, or 3, α 1i is the size of duty cycle α1, duty cycle α2 or duty cycle α3 determined by simulation method, α 2i is the size of duty cycle α1, duty cycle α2 or duty cycle α3 determined by experimental test method, α 3i is the size of duty cycle α1, duty cycle α2 or duty cycle α3 determined by the expert system method, A1 is α 1i The weight coefficient of A2 is α 2i The weight coefficient of A3 is α 3i The weight coefficient of 1i is the size of period T1, period T2, and period T3 determined by simulation method, T2i is the size of period T1, period T2, and period T3 determined by simulation method, T 3i is the size of period T1, period T2, and period T3 determined by the expert system method, B1 is α 1i The weight coefficient of B2 is α 2i The weight coefficient of B3 is α 3i The weight coefficient of .

[0028] In this embodiment, A1, A2, A3, and B1, B2, B3 are weight coefficients determined by training with a large amount of historical data through a reinforcement learning algorithm.

[0029] In this embodiment, the simulation method is a Simulink simulation method.

[0030] In this embodiment, the controller in step S2 adjusts the output duty cycle of the PWM module according to the sampled current signal so that the output current is as close as possible to the main pull-up current, the auxiliary pull-up current or the buffer current defined in the third-order current drive model, and an improved PID controller model is used to implement it. In the improved PID controller model, a low-pass filter is introduced in the differential link of the conventional PID to solve the high-frequency interference introduced by the differential regulation and reduce the instability caused by the sudden change of error disturbance.

[0031] In this embodiment, the selection of the energy storage inductor in the buck-boost chopper circuit is based on the formula Where, R is the load resistance, αi is the duty cycle α1, duty cycle α2 or duty cycle α3, and f is the switching frequency of the MOS tube.

[0032] In this embodiment, the controller is an ARM controller.

[0033] In specific implementation, the schematic diagram of the buck-boost chopper circuit is as follows: Figure 3 As shown, when the MOS tube V is in the on state, the power supply E supplies energy to the inductor L through the MOS tube V, and the load is powered through the capacitor C. When the MOS tube V is in the off state, the inductor L stops charging, and the capacitor C and the load are powered through the freewheeling diode VD.

[0034] When the hydrogen injector solenoid valve is energized, the electromagnetic coil of the hydrogen injector solenoid valve generates electromagnetic suction force, attracting the armature to overcome the return spring force. When the electromagnetic suction force is greater than the return spring force, the armature, together with the needle valve and the small ball, rises until the armature contacts the fixed iron core, and a non-complete elastic collision occurs, resulting in vibration jumps. Finally, under the action of the electromagnetic force, the kinetic energy is completely converted into elastic potential energy, and the hydrogen injector remains in the open state; when the hydrogen injector solenoid valve is powered off, since the electromagnetic coil is an inductive load, the electromagnetic force does not completely disappear at this time, but gradually decreases under the action of inductance. When the electromagnetic force is less than the spring force, the armature begins to descend under the action of the return spring. When the small ball falls and contacts the valve seat, a non-complete elastic collision occurs again, and vibration jumps are generated again.

[0035] The above method of the present invention can well reduce the vibration jump problem generated when the solenoid valve of the hydrogen injector is opened; and reduce the vibration jump problem generated when the solenoid valve of the hydrogen injector is closed.

[0036] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0037] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0038] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0039] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0040] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A needle valve seating bounce drive control method for a direct injection hydrogen engine injector, wherein the control system adopted comprises a controller, a PWM module, a buck-boost chopper circuit, a MOS tube and a current sampling module, wherein the controller, the PWM module, the buck-boost chopper circuit and the MOS tube are connected in sequence, the MOS tube is connected to the electromagnetic coil of the hydrogen injector solenoid valve, and the current sampling module is respectively connected to the electromagnetic coil of the hydrogen injector solenoid valve and the controller; characterized in that: The needle valve seating rebound drive control method comprises the following steps: Step S1, the controller constructs a third-order current drive model, in which the third-order current drive model defines the magnitude and duration of a main pull-up current for controlling the full opening of the hydrogen injector solenoid valve, the magnitude and duration of a secondary pull-up current for reducing the vibration jump amplitude generated when the hydrogen injector solenoid valve is opened, and the magnitude and duration of a buffer current for reducing the vibration jump amplitude generated when the hydrogen injector solenoid valve is closed; Step S2, the controller controls the PWM module to output three PWM pulse signals with a duty cycle of α1 and a period of T1, a duty cycle of α2 and a period of T2, and a duty cycle of α3 and a period of T3 to the MOS tube in sequence according to the main pull-up current size and duration, the auxiliary pull-up current size and duration, and the buffer current size and duration defined in the third-order current drive model, and then transmits them to the electromagnetic coil of the hydrogen injector solenoid valve, and provides the main pull-up current to the electromagnetic coil of the hydrogen injector solenoid valve through the PWM pulse signal with a duty cycle of α1 and a period of T1, and provides the auxiliary pull-up current to the electromagnetic coil of the hydrogen injector solenoid valve through the PWM pulse signal with a duty cycle of α2 and a period of T2, so as to reduce the vibration jump problem generated when the hydrogen injector solenoid valve is opened; and provides the buffer current to the electromagnetic coil of the hydrogen injector solenoid valve through the PWM pulse signal with a duty cycle of α3 and a period of T2, so as to reduce the vibration jump problem generated when the hydrogen injector solenoid valve is closed; wherein, α1>α2>α3; During the execution of step S2, the current sampling module samples the current of the electromagnetic coil and outputs the sampled current signal to the controller. The controller adjusts the output duty cycle of the PWM module according to the sampled current signal to make the output current as close as possible to the main pull-up current, auxiliary pull-up current or buffer current defined in the third-order current drive model.

2. The needle valve seating bounce drive control method of the direct injection hydrogen engine injector according to claim 1, characterized in that: The controller constructs a third-order current drive model by combining simulation with experimental testing and expert system, and constructs a function αi=A1α based on the duty cycle multi-parameter model. 1i +A2α 2i +A3α 3i Calculate the duty cycle α1, duty cycle α2, and duty cycle α3, and construct the function Ti=B1T based on the periodic multi-parameter model 1i +B2T 2i +B3T 3i Calculate the size of period T1, period T2, and period T3; where i is 1, 2, or 3, α 1i is the size of duty cycle α1, duty cycle α2 or duty cycle α3 determined by simulation method, α 2i is the size of duty cycle α1, duty cycle α2 or duty cycle α3 determined by experimental test method, α 3i is the size of duty cycle α1, duty cycle α2 or duty cycle α3 determined by the expert system method, A1 is α 1i The weight coefficient of A2 is α 2i The weight coefficient of A3 is α 3i The weight coefficient of 1i is the size of period T1, period T2, and period T3 determined by simulation method, T 2i is the size of period T1, period T2, and period T3 determined by simulation method, T 3i is the size of period T1, period T2, and period T3 determined by the expert system method, B1 is α 1i The weight coefficient of B2 is α 2i The weight coefficient of B3 is α 3i The weight coefficient of .

3. The needle valve seating bounce drive control method of the direct injection hydrogen engine injector according to claim 1, characterized in that: A1, A2, A3, and B1, B2, B3 are weight coefficients determined by training with a large amount of historical data through a reinforcement learning algorithm.

4. The needle valve seating bounce drive control method of a direct injection hydrogen engine injector according to claim 1, characterized in that: The simulation method is a Simulink simulation method.

5. The needle valve seating bounce drive control method of the direct injection hydrogen engine injector according to claim 1, characterized in that: In step S2, the controller adjusts the output duty cycle of the PWM module according to the sampled current signal so that the output current is as close as possible to the main pull-up current, the auxiliary pull-up current or the buffer current defined in the third-order current drive model. An improved PID controller model is used to implement it. In the improved PID controller model, a low-pass filter is introduced in the differential link of the conventional PID to solve the high-frequency interference introduced by the differential regulation and reduce the instability caused by the sudden change of error disturbance.

6. The needle valve seating bounce drive control method of the direct injection hydrogen engine injector according to claim 1, characterized in that: The selection of the energy storage inductor in the buck-boost chopper circuit is based on the formula Where, R is the load resistance, αi is the duty cycle α1, duty cycle α2 or duty cycle α3, and f is the switching frequency of the MOS tube.

7. The needle valve seating bounce drive control method of a direct injection hydrogen engine injector according to claim 1, characterized in that: The controller is an ARM controller.

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