Hybrid power system and control method for gasoline compression ignition engines in vehicles

Abstract

This invention discloses a hybrid power system for a gasoline compression ignition engine in a vehicle, comprising: a gasoline compression ignition engine; a generator; an electric motor; a first planetary gear connected to both the gasoline compression ignition engine and the generator; a second planetary gear mounted on the vehicle frame and connected to the electric motor; an output shaft connected to both the first and second planetary gears, extending from the second planetary gear to connect to the vehicle wheels via a reducer; an engine clutch connected to both the gasoline compression ignition engine and the first planetary gear; an electric motor clutch connected to both the electric motor and the second planetary gear; an engine lock-up clutch connected to both the gasoline compression ignition engine and the vehicle frame; and a generator lock-up clutch connected to both the generator and the vehicle frame. This structure alters the transmission relationship between the gasoline compression ignition engine, the generator, the electric motor, and the output shaft, thereby changing the vehicle's drive mode.

Description

Technical Field

[0001] At least one embodiment of the present invention relates to the field of automotive powertrain technology, and more particularly to a hybrid powertrain system and control method for a gasoline compression ignition engine for a vehicle. Background Technology

[0002] Internal combustion engines consume a large amount of oil annually. With energy issues becoming increasingly severe, many countries have recently set emission reduction targets for carbon peaking and carbon neutrality, necessitating the development of related technologies to improve the energy efficiency of the automotive industry. Currently, in addition to improving the thermal efficiency of the internal combustion engine itself, developing hybrid power systems that couple internal combustion power with electric drive has also become an effective way to improve energy efficiency.

[0003] Existing hybrid power configurations all have certain limitations. Series configurations involve multiple energy conversions, resulting in low system efficiency at high speeds. Parallel configurations, with mechanical coupling between the engine and output shaft, struggle to ensure efficient engine operation. Gasoline compression ignition (GCI) engines are currently a hot research topic in the field of internal combustion engines. Their advantages include easier initial emission control (NOx, soot) compared to diesel engines, and the ability to achieve comparable thermal efficiency under certain operating conditions. However, existing gasoline compression ignition engines suffer from poor combustion stability under low load and start-up conditions, rough combustion under high load conditions, and, due to the low viscosity of gasoline, lower injection pressure under high load conditions for the same NOx emissions, resulting in lower thermal efficiency compared to diesel compression ignition engines.

[0004] Because the power-split hybrid system has the characteristic of dual decoupling of engine speed and torque, combining the gasoline compression ignition engine with the power-split hybrid system can give full play to the advantages of both, so that the gasoline compression ignition engine can effectively avoid unstable operation and rough operation conditions, thereby improving the system's energy efficiency while reducing raw emissions.

[0005] However, the complex operating mode of power-split hybrid systems, involving multiple speed-torque couplings, presents significant challenges to the development of control methods. Furthermore, most current gasoline compression ignition engines are either modified diesel engines with refueling or gasoline engines with spark plugs removed. Therefore, there is a lack of existing technology for a power-split hybrid system using a gasoline compression ignition engine. Summary of the Invention

[0006] In view of this, embodiments of the present invention provide a hybrid power system for a gasoline compression ignition engine in a vehicle. By setting a first planetary gear to connect the gasoline compression ignition engine and the generator respectively, setting a second planetary gear to connect the electric motor, and connecting the first planetary gear and the second planetary gear to the output shaft respectively, multiple transmission relationships between the gasoline compression ignition engine, the generator and the electric motor and the output shaft are realized, and torque is output through the output shaft to the wheels.

[0007] According to an embodiment of the present invention, a hybrid power system for a gasoline compression ignition engine in a vehicle is provided, comprising: a gasoline compression ignition engine; a generator; an electric motor; a first planetary gear connected to the gasoline compression ignition engine and the generator respectively; a second planetary gear mounted on the vehicle frame and connected to the electric motor; an output shaft connected to the first planetary gear and the second planetary gear, and extending from the second planetary gear to connect to the wheels of the vehicle via a reducer; an engine clutch connected to the gasoline compression ignition engine and the first planetary gear respectively; an electric motor clutch connected to the electric motor and the second planetary gear respectively; an engine lock-up clutch connected to the gasoline compression ignition engine and the vehicle frame respectively; and a generator lock-up clutch connected to the generator and the vehicle frame respectively; wherein, by controlling the engagement or disengagement of the engine clutch, the electric motor clutch, the engine lock-up clutch, and the generator lock-up clutch respectively, the transmission relationship between the gasoline compression ignition engine, the generator, and the electric motor and the output shaft is changed to switch the driving mode of the vehicle.

[0008] According to an embodiment of the present invention, the first planetary gear includes: a first planet carrier connected to the gasoline compression ignition engine; a first sun gear meshing with a first planet gear mounted on the first planet carrier and connected to the generator; and a first ring gear meshing with the first planet gear mounted on the first planet carrier and connected to a first end of the output shaft; wherein, the engine clutch is disposed between the gasoline compression ignition engine and the first planet carrier to control the connection or disconnection of the gasoline compression ignition engine from the first planet carrier, so that when the gasoline compression ignition engine is connected to the first planet carrier, the gasoline compression ignition engine drives the first planet carrier, the first ring gear, the first sun gear, and the output shaft to rotate, and the first sun gear drives the generator to generate electricity.

[0009] According to an embodiment of the present invention, the second planetary gear includes: a second sun gear connected to the electric motor; a second planet carrier connected to the output shaft such that a second planetary gear mounted on the second planet carrier meshes with the second sun gear, and a second end of the output shaft extends from the second planet carrier; and a second ring gear mounted on the vehicle frame and meshing with the second planetary gear mounted on the second planet carrier; wherein the electric motor clutch is disposed between the electric motor and the second sun gear to control the connection or disconnection of the electric motor and the second sun gear, so that when the electric motor is connected to the second sun gear, the electric motor drives the second sun gear, the second planet carrier, and the output shaft to rotate.

[0010] According to an embodiment of the present invention, a control method for the above-described hybrid power system for a gasoline compression ignition engine in a vehicle is also provided, comprising: acquiring the vehicle's brake pedal travel C. b If the brake pedal travel C b If the brake pedal travel C > 0, then the vehicle is controlled to execute the braking mode; if the brake pedal travel C b =0, then obtain the accelerator pedal travel C. f And determine the vehicle's current target torque T. req ; and according to the target torque T req The relationship between the target torque T and the torque range at the output shaft when the vehicle is operating in power-split mode determines the type of drive mode the vehicle currently needs to execute; wherein, the target torque T req The accelerator pedal travel C f The product of the maximum torque required by the vehicle at the current speed.

[0011] According to an embodiment of the present invention, if the target torque T req Less than the minimum torque T at the output shaft when the vehicle is running in power-split mode. reqd Then obtain the current SOC of the power battery. act If the current power battery charge SOC act The state of charge (SOC) of the power battery is greater than the low charge threshold. low Then the vehicle is controlled to execute pure electric drive mode; if the current power battery charge SOC... act Less than the low charge threshold SOC of the power battery low If the target torque T is..., then control the vehicle to execute engine drive mode; req Greater than the maximum torque T at the output shaft when the vehicle is running in power-split mode requ If the target torque T is..., then control the vehicle to execute a hybrid drive mode; and if the target torque T... req The minimum torque T at the output shaft when the vehicle is operating in power-split mode. reqdWith the maximum value T requ Between these, the vehicle is controlled to execute a power split mode.

[0012] According to an embodiment of the present invention, controlling the vehicle to perform a power split mode includes: closing the engine clutch, closing the electric motor clutch, disengaging the engine lock-up clutch, and disengaging the generator lock-up clutch, such that the gasoline compression ignition engine drives the output shaft to rotate via the first planetary gear, the generator outputs negative torque to balance the torque transmitted from the gasoline compression ignition engine to the generator via the first planetary gear and generates electricity, and the electric motor drives the output shaft to rotate via the second planetary gear.

[0013] According to an embodiment of the present invention, the control of the vehicle to perform the power split mode further includes: obtaining the average vehicle speed v within 30 seconds during the vehicle's driving process based on the road conditions. avg Average acceleration a avg And the ratio of idling time to r i The average vehicle speed v avg The average acceleration a avg and the idle time ratio r i Input to the fuzzy controller, output the current operating condition category of the vehicle; obtain the current vehicle speed v. i (t), absolute acceleration a i (t) and the SOC of the power battery i (t); the working condition category and the vehicle speed v i (t), the absolute acceleration a i (t), the SOC of the power battery i (t) and the target torque T req Input the optimal equivalent factor neural network model corresponding to the operating condition category, and output the optimal equivalent factor λ; and based on the optimal equivalent factor λ and the accelerator pedal travel C... f The optimal torque distribution ratio of the gasoline compression ignition engine, the generator, and the electric motor is calculated based on the boundary conditions of the operating conditions of the gasoline compression ignition engine and the objective function of the energy consumption minimization control strategy.

[0014] According to an embodiment of the present invention, controlling the vehicle to execute the power split mode further includes: controlling the vehicle to execute the engine start mode before closing the engine clutch, including: closing the engine lock-up clutch, disengaging the generator lock-up clutch, disengaging the engine clutch, disengaging the electric motor clutch, so that the generator outputs torque T for starting the gasoline compression ignition engine. gs The gasoline compression ignition engine is driven by the first planetary gear to rotate to the minimum speed n, which is the speed at which the gasoline compression ignition engine achieves stable combustion and low initial emissions.ed ; and disengage the engine lock-up clutch and close the engine clutch so that the gasoline compression ignition engine outputs torque through the output shaft.

[0015] According to an embodiment of the present invention, controlling the vehicle to execute a pure electric drive mode includes: disengaging the engine clutch, engaging the electric motor clutch, engaging the engine lock-up clutch, and disengaging the generator lock-up clutch, causing the gasoline compression ignition engine to stop, and the electric motor driving the output shaft to rotate via the second planetary gear, thereby driving the wheels to rotate; and / or, controlling the vehicle to execute an engine drive mode includes: engaging the engine clutch, disengaging the electric motor clutch, disengaging the engine lock-up clutch, and disengaging the generator lock-up clutch, causing the electric motor to stop, and the gasoline compression ignition engine driving the output shaft to rotate via the first planetary gear, thereby driving the wheels to rotate, and the generator outputting negative torque to balance the torque transmitted from the gasoline compression ignition engine to the generator via the first planetary gear and generate electricity; and / or, controlling the vehicle to execute a hybrid drive mode includes: engaging the engine clutch, engaging the electric motor clutch, engaging the generator lock-up clutch, and disengaging the engine lock-up clutch, causing the generator to stop, and the gasoline compression ignition engine driving the output shaft to rotate via both the first planetary gear and the electric motor driving the second planetary gear, thereby driving the wheels to rotate.

[0016] According to an embodiment of the present invention, during the execution of the braking mode, the electric motor clutch is closed, the engine clutch is disengaged, the engine lock-up clutch is disengaged, and the generator lock-up clutch is disengaged, so that the gasoline compression ignition engine and the generator stop, the electric motor outputs negative torque to cooperate with the vehicle's brake pads for braking, and recovers part of the energy during the braking process.

[0017] According to the above embodiments of the present invention, a hybrid power system for a gasoline compression ignition engine for a vehicle is provided by setting a first planetary gear to connect the gasoline compression ignition engine and the generator respectively, setting a second planetary gear to connect the electric motor, and connecting the first planetary gear and the second planetary gear to the output shaft respectively. By setting an engine clutch, an electric motor clutch, an engine lock-up clutch and a generator lock-up clutch respectively, the transmission relationship between the gasoline compression ignition engine, the generator and the electric motor and the output shaft is changed, and the torque is output to the wheels through the output shaft to switch the driving mode of the vehicle. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the hybrid power system of a gasoline compression ignition engine for a vehicle according to the present invention.

[0019] Figure 2 This is a flowchart of the control method for a hybrid power system of a gasoline compression ignition engine for a vehicle according to the present invention.

[0020] Figure 3 This is a flowchart of determining the optimal torque distribution among the engine, generator, and electric motor when the vehicle executes the power splitting mode of this invention;

[0021] Figure 4 This is a flowchart for establishing an optimal equivalent factor neural network model corresponding to the working condition category;

[0022] Figure 5 This is a diagram showing the operating characteristics of a gasoline compression ignition engine using traditional control methods.

[0023] Figure 6 This is a diagram showing the operating characteristics of a gasoline compression ignition engine using the control method of this invention;

[0024] Figure 7 It is the vehicle speed following curve under the control method of the present invention;

[0025] Figure 8 It is the engine start-stop curve of the vehicle under the control method of the present invention;

[0026] Figure 9 This is a comparison diagram of the operating condition distribution of a gasoline compression ignition engine under the control method of the present invention and under the conventional control method.

[0027] Figure 10 The diagram shows the change in battery charge during cycling under the control method of this invention and under a conventional control method; and

[0028] Figure 11 This is a graph showing the change in cyclic fuel consumption under the control method of this invention and under the conventional control method.

[0029] In the picture:

[0030] 1-Gasoline compression ignition engine; 11-Engine clutch; 12-Engine lock-up clutch;

[0031] 2-Generator; 21-Generator lock-up clutch;

[0032] 3-Electric motor; 31-Electric motor clutch;

[0033] 4-First planetary gear; 41-First planet carrier; 42-First sun gear; 43-First ring gear; 44-First planetary gear;

[0034] 5-Second planetary gear; 51-Second sun gear; 52-Second planet carrier; 53-Second ring gear; 54-Second planetary gear;

[0035] 6-Frame;

[0036] 7-Output shaft; 71-First end; 72-Second end. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0038] According to one aspect of the inventive concept of the present invention, a hybrid power system for a gasoline compression ignition engine in a vehicle is provided, comprising: a gasoline compression ignition engine; a generator; an electric motor; a first planetary gear connected to both the gasoline compression ignition engine and the generator; a second planetary gear mounted on the vehicle frame and connected to the electric motor; an output shaft connected to both the first and second planetary gears, extending from the second planetary gear to connect to the vehicle wheels via a reduction gear; an engine clutch connected to both the gasoline compression ignition engine and the first planetary gear; an electric motor clutch connected to both the electric motor and the second planetary gear; an engine lock-up clutch connected to both the gasoline compression ignition engine and the vehicle frame; and a generator lock-up clutch connected to both the generator and the vehicle frame. The transmission relationship between the gasoline compression ignition engine, the generator, and the electric motor and the output shaft is changed by controlling the engagement or disengagement of the engine clutch, the electric motor clutch, the engine lock-up clutch, and the generator lock-up clutch, respectively, thereby switching the vehicle's drive mode.

[0039] Figure 1 This is a schematic diagram of the hybrid power system of a gasoline compression ignition engine for a vehicle according to the present invention.

[0040] According to an exemplary embodiment of the present invention, please refer to Figure 1A hybrid power system for a gasoline compression ignition engine in a vehicle is provided, comprising a gasoline compression ignition engine 1, a generator 2, an electric motor 3, a first planetary gear 4, a second planetary gear 5, an output shaft 7, an engine clutch 11, an electric motor clutch 31, an engine lock-up clutch 12, and a generator lock-up clutch 21. The first planetary gear 4 is connected to both the gasoline compression ignition engine 1 and the generator 2. The second planetary gear 5 is mounted on the vehicle frame 6 and connected to the electric motor 3. The output shaft 7 is connected to both the first planetary gear 4 and the second planetary gear 5, and extends from the second planetary gear 5 to connect to the vehicle wheels via a reduction gear. The engine clutch 11 is connected to both the gasoline compression ignition engine 1 and the first planetary gear 4. The electric motor clutch 31 is connected to both the electric motor 3 and the second planetary gear 5. The engine lock-up clutch 12 is connected to both the gasoline compression ignition engine 1 and the vehicle frame 6. The generator lock-up clutch 21 is connected to both the generator 2 and the vehicle frame 6. Specifically, by controlling the engagement or disengagement of the engine clutch 11, electric motor clutch 31, engine lock-up clutch 12, and generator lock-up clutch 21 respectively, the transmission relationship between the gasoline compression ignition engine 1, generator 2, and electric motor 3 and the output shaft 7 is changed to switch the vehicle's drive mode.

[0041] In this embodiment, a first planetary gear 4 is provided to connect the gasoline compression ignition engine 1 and the generator 2 respectively, and a second planetary gear 5 is provided to connect the electric motor 3. The first planetary gear 4 and the second planetary gear 5 are respectively connected to the output shaft 7. By providing an engine clutch 11, an electric motor clutch 31, an engine lock-up clutch 12, and a generator lock-up clutch 21 respectively, the transmission relationship between the gasoline compression ignition engine 1, the generator 2, and the electric motor 3 and the output shaft 7 is changed, and torque is output to the wheels through the output shaft 7 to switch the vehicle's driving mode.

[0042] In some exemplary embodiments, reference is made to Figure 1 The first planetary gear 4 includes a first planet carrier 41, a first sun gear 42, and a first ring gear 43. The first planet carrier 41 is connected to the gasoline compression ignition engine 1. The first sun gear 42 meshes with the first planet gear 44 mounted on the first planet carrier 41 and is connected to the generator 2. The first ring gear 43 meshes with the first planet gear 44 mounted on the first planet carrier 41 and is connected to the first end 71 of the output shaft 7. An engine clutch 11 is disposed between the gasoline compression ignition engine 1 and the first planet carrier 41 to control the connection or disconnection of the gasoline compression ignition engine 1 and the first planet carrier 41. When the gasoline compression ignition engine 1 is connected to the first planet carrier 41, the gasoline compression ignition engine 1 drives the first planet carrier 41, the first ring gear 43, the first sun gear 42, and the output shaft 7 to rotate, and the first sun gear 42 drives the generator 2 to generate electricity.

[0043] In some exemplary embodiments, reference is made to Figure 1 The second planetary gear 5 includes a second sun gear 51, a second planet carrier 52, and a second ring gear 53. The second sun gear 51 is connected to the electric motor 3. The second planet carrier 52 is connected to the output shaft 7, such that the second planet gear 54 mounted on the second planet carrier 52 meshes with the second sun gear 51, and the second end 72 of the output shaft 7 extends out from the second planet carrier 52. The second ring gear 53 is mounted on the vehicle frame 6 and meshes with the second planet gear 54 mounted on the second planet carrier 52. An electric motor clutch 31 is disposed between the electric motor 3 and the second sun gear 51 to control the connection or disconnection of the electric motor 3 and the second sun gear 51, so that when the electric motor 3 is connected to the second sun gear 51, the electric motor 3 drives the second sun gear 51, the second planet carrier 52, and the output shaft 7 to rotate.

[0044] According to the above embodiments of the present invention, a hybrid power system for a gasoline compression ignition engine for a vehicle is provided by setting a first planetary gear 4 to connect the gasoline compression ignition engine 1 and the generator 2 respectively, setting a second planetary gear 5 to connect the electric motor 3, and connecting the first planetary gear 4 and the second planetary gear 5 to the output shaft 7 respectively. By setting an engine clutch 11, an electric motor clutch 31, an engine lock-up clutch 12 and a generator lock-up clutch 21 respectively, the transmission relationship between the gasoline compression ignition engine 1, the generator 2 and the electric motor 3 and the output shaft 7 is changed, and torque is output to the wheels through the output shaft 7 to switch the driving mode of the vehicle.

[0045] Figure 2 This is a flowchart of the control method for a hybrid power system of a gasoline compression ignition engine for a vehicle according to the present invention.

[0046] According to an exemplary embodiment of the present invention, please refer to Figure 2 A control method for a hybrid power system of a gasoline compression ignition engine for a vehicle, comprising: acquiring the vehicle's brake pedal travel C b If the brake pedal travel C b If the brake pedal travel is greater than 0, then the vehicle will be controlled to enter braking mode. b =0, then obtain the accelerator pedal travel C. f And determine the vehicle's current target torque T. req According to the target torque T req The relationship between the torque range at output shaft 7 and the torque range when the vehicle is operating in power-split mode determines the type of drive mode the vehicle needs to execute. The target torque T... req The accelerator pedal travel C f The product of C and the maximum torque required by the vehicle at the current speed. b =0 belongs to Figure 2 C inb Cases where the value is not greater than zero.

[0047] It should be noted that in this embodiment, based on the "vehicle speed-maximum required torque" test data of vehicles of the same mass obtained from experiments, a MAP (maximum driving torque curve of the engine at different vehicle speeds under common operating conditions) is established. The horizontal axis of this MAP represents vehicle speed, and the vertical axis represents the maximum required torque of the vehicle at that speed. Based on this MAP and the current vehicle speed, the maximum required torque T of the vehicle at the current moment is determined. mreq Therefore, at the current moment, the target torque at output shaft 7 is:

[0048] T req =T mreq C f .................................(1)

[0049] In some exemplary embodiments, reference continues to be made to Figure 2 If the target torque T req Less than the minimum torque T at output shaft 7 when the vehicle is running in power-split mode. reqd Then obtain the current SOC of the power battery. act If the current state of charge (SOC) of the power battery is... act The state of charge (SOC) of the power battery is greater than the low charge threshold. low Then the vehicle will be controlled to operate in pure electric drive mode; if the current state of charge (SOC) of the power battery is... act Less than the low charge threshold SOC of the power battery low If the target torque T is..., then control the vehicle to execute engine drive mode; req The torque at output shaft 7 is greater than the maximum value T when the vehicle is running in power-split mode. requ Then control the vehicle to execute hybrid drive mode; if the target torque T req The minimum torque T at output shaft 7 when the vehicle is operating in power-split mode. reqd With the maximum value T requ Between these, the vehicle is controlled to execute a power split mode.

[0050] It should be noted that, in this embodiment, the maximum torque T at the output shaft 7 is measured when the vehicle is running in power-split mode. requ for:

[0051]

[0052] Among them, T eu The maximum torque in the stable combustion and low initial emission torque range of a gasoline compression ignition engine; T muk represents the maximum output torque of motor 3 at the current vehicle speed. p1 The characteristic parameter of the first planetary gear 4 is the ratio of the number of teeth on the first ring gear 43 to the number of teeth on the first sun gear 42; k p2 These are the characteristic parameters of the second planetary gear 5.

[0053] In this embodiment, the minimum torque T at the output shaft 7 when the vehicle is running in power-split mode reqd for:

[0054]

[0055] Among them, T ed The minimum torque within the stable combustion and low initial emission torque range of a gasoline compression ignition engine; the current state of charge (SOC) of the power battery. act Less than the low charge threshold SOC of the power battery low This is considered as insufficient power battery charge.

[0056] In some exemplary embodiments, reference is made to Figure 1 The control of the vehicle to perform power split mode includes closing the engine clutch 11, closing the electric motor clutch 31, disengaging the engine lock-up clutch 12, and disengaging the electric motor lock-up clutch 21, so that the gasoline compression ignition engine 1 drives the output shaft 7 to rotate via the first planetary gear 4, the generator 2 outputs negative torque to balance the torque transmitted from the gasoline compression ignition engine 1 to the generator 2 via the first planetary gear 4 and generate electricity, and the electric motor 3 drives the output shaft 7 to rotate via the second planetary gear 5.

[0057] Figure 3 This is a flowchart of determining the optimal torque distribution among the engine, generator, and electric motor when the vehicle executes the power splitting mode of this invention.

[0058] In some exemplary embodiments, reference is made to Figure 3 Controlling the vehicle to execute power split mode also includes obtaining the average vehicle speed v over 30 seconds based on road conditions. avg Average acceleration a avg And the ratio of idling time to r i The average vehicle speed v avg Average acceleration a avg And the ratio of idling time to r i Input to the fuzzy controller, output the current operating condition category of the vehicle, for example Figure 3 The diagram shows operating conditions 1, 2, and 3. The current vehicle speed v is obtained. i (t), absolute acceleration a i (t) and the SOC of the power battery i (t). The operating condition category and vehicle speed v i(t), absolute acceleration a i (t), SOC of power battery i (t) and target torque T req Input the optimal equivalent factor neural network model corresponding to the operating condition category, and output the optimal equivalent factor λ. Based on the optimal equivalent factor λ and the accelerator pedal travel C... f The optimal torque distribution ratio of gasoline compression ignition engine 1, generator 2 and electric motor 3 is calculated by applying the boundary conditions of the operating conditions of the gasoline compression ignition engine to the objective function of the energy consumption minimization control strategy.

[0059] It should be noted that, in this embodiment, the fuzzy controller is obtained in the following way:

[0060] ① Obtain the vehicle's state information within the time interval [t-30s, t] during its driving process using sensors, and select the average vehicle speed v within this time interval. avg Average acceleration a avg Compared to idling time, r i As a feature parameter.

[0061] ②Regarding the average vehicle speed v avg Average acceleration a avg Compared to idling time, r i These three feature parameters are used to establish a trapezoidal membership function, and through repeated modification and verification, fuzzy rules are constructed.

[0062] ③ Use this fuzzy rule to establish a fuzzy controller. The fuzzy controller can perform real-time operating condition identification based on the state information of the vehicle during the driving process [t-30s,t] obtained by the sensor, and relatively accurately reflect the current driving condition type, such as condition 1, condition 2, and condition 3.

[0063] Figure 4 This is a flowchart for establishing an optimal equivalent factor neural network model corresponding to the operating condition category.

[0064] Furthermore, in this embodiment, referring to Figure 4 The optimal equivalent factor neural network model corresponding to the working condition category is established in the following way:

[0065] (1) Obtain the time-varying function λ of the optimal equivalent factor under each working condition. i (t).

[0066] First, offline optimization of power allocation is performed. The specific process is as follows:

[0067] Feature parameters were extracted from the data at all time points for each driving condition, and the vehicle speed v(t) and vehicle acceleration a(t) at all time points for each condition were extracted respectively.

[0068] The target torque T at the output shaft at various time points under different driving conditions was calculated using the vehicle's longitudinal dynamics model. req :

[0069]

[0070] α wheel =Δω wheel / Δt................................................(5)

[0071] v = 3.6ω wheel R wheel ..................................................(6)

[0072] Where: m is the vehicle's curb weight; C d Where A is the air resistance coefficient; A is the vehicle's frontal area; f g denoted as ρ, where α is the ground rolling resistance coefficient; α is the vehicle acceleration; J eng J ISG J wheel These are the moments of inertia of the engine, motor, and wheels, respectively; α wheel ω is the wheel's angular acceleration. wheel R is the wheel angular velocity; wheel denoted as wheel radius; v is vehicle speed.

[0073] For different driving conditions, offline optimization using dynamic programming algorithm is performed, with the following steps:

[0074] ① Initialize the dynamic programming algorithm by defining the time step and state storage space.

[0075] ② Obtain the vehicle speed v(i) and the target torque T at the output shaft for this operating condition within N stages. req (i), i = N, N-1, ..., 1.

[0076] ③ For the vehicle speed v(i) corresponding to stage i and the target torque T at the output shaft req (i) The output torque T of the gasoline compression ignition engine eng (i) is the control variable, and the SOC(i) of the power battery is used as the state constraint. The output torque T of the gasoline compression ignition engine is calculated at each stage i. eng (i,j) represents the SOC(i,j) of the power battery from the lower limit to the upper limit, and the formula is:

[0077] SOC(i,j)=SOC(i+1,j)+η bat ∫(Pmot -P gen )dt....(7)

[0078] in:

[0079] SOC(N,j)=SOC fin .........................................(8)

[0080] P mot =Φ(ω) mot T mot )....................................(9)

[0081] P gen =Ψ(ω) gen T gen )......................................(10)

[0082] ω shaft =ω wheel k shaft ...........................................(11)

[0083] ω mot =ω shaft (1+k p2 ).......................................(12)

[0084]

[0085] ω gen =(1+k) p1 )ω eng (i,j)-k p1 ω shaft .............(14)

[0086]

[0087] ω eng =g(T) eng ).............................................(16)

[0088] In the formula, SOC(i,j) represents the power battery charge; η bat For the charging and discharging efficiency of the power battery; Pmot P represents the power of the electric motor. gen The generator power is the power of the motor and generator; when the power is positive, the motor consumes electrical energy, and when the power is negative, the generator produces electrical energy. SOC (State of Charge) fin ω represents the expected charge level of the power battery at the end of the operating cycle. mot T represents the motor speed. mot ω represents the motor torque. gen T is the generator speed; gen ω represents the generator torque. shaft k is the angular velocity at the output shaft. shaft T is the gear ratio of the final drive located between the rear wheels and the output shaft; req (i) represents the target torque at the output shaft; T eng (i,j) represents the output torque of the gasoline compression ignition engine; ω eng (i,j) represents a gasoline compression ignition engine with torque T. eng The engine speed corresponding to the optimal fuel consumption condition during operation (i,j) is obtained from the MAP difference of the universal characteristics of the gasoline compression ignition engine, and its functional relationship is expressed by g(T). eng ) represents; Φ(ω) mot T mot Ψ(ω) represents the functional relationship between motor power, motor speed, and motor torque, obtained from the difference in the motor's operating characteristics (MAP); gen T gen The expression indicates that the functional relationship between generator power, generator speed, and torque is obtained from the difference in generator operating characteristics (MAP).

[0089] ④ Calculate the output torque T of the gasoline compression ignition engine at each stage i. eng The fuel consumption m corresponding to (i,j) fuel (i,j):

[0090] m fuel (i,j)=f[ω eng (i,j),T eng (i,j)]........................(17)

[0091] In the formula, f[ω eng (i,j),T eng [i,j)] represents the functional relationship between fuel consumption of a gasoline compression ignition engine and engine speed and torque, obtained from the difference in the universal characteristic MAP of the gasoline compression ignition engine.

[0092] ⑤ For stage i, define stage cost K j (i), combined with the cost K from the previous stage j (i+1) Calculate the optimal value of the cost function

[0093] K = min[K] j (i)+K j (i+1)]................................(18)

[0094] That is, the discretization control objective is:

[0095]

[0096] The constraints satisfy:

[0097] SOC(i+1)=SOC(i)-∫(P mot -P gen )dt,i=0,1,…,N-1(20)

[0098] SOC min ≤SOC≤SOC max ....................................(twenty one)

[0099]

[0100] P eng ∈P GCI ........................................................(twenty three)

[0101] ω eng ∈ω GCI ......................................................(twenty four)

[0102] T eng ∈T GCI ........................................................(25)

[0103] (.) min and(.) max These represent the minimum and maximum values, respectively; SOC represents the battery charge; P bat Indicates battery power; P GCI ω GCI and T GCI These represent the power, speed, and torque ranges within which a gasoline compression ignition engine can achieve stable combustion and low raw emissions.

[0104] ⑥ Set stage i = i-1, repeat step ⑤ until i = 1, and obtain the control quantity change function T that minimizes the cost function. eng (i), and the corresponding ω eng (i), ω mot (i), ω gen (i), T m o t (i) and T gen (i), where:

[0105] ω eng (i)=g(T eng (i))........................................(26)

[0106] ω mot (i)=ω shaft (i)(1+k p2 )................(27)

[0107] ω gen (i)=(1+k p1 )ω eng (i)-k p1 ω shaft (i)...............(28)

[0108]

[0109]

[0110] ⑦ Establish the cost expression:

[0111] J(k)=m fuel (k)+λ(k)P bat (k)........................(31)

[0112] in:

[0113] m fuel (k)=f[ω eng (k),T eng (k)]........................(32)

[0114] P bat (k)=P mot (k)-P gen (k)........................(33)

[0115] P mot (k)=Φ[ω mot (k), T mot (k)]........................(34)

[0116] P gen (k)=Ψ[ω gen (k), T gen (k)]........................(35)

[0117] Because from step ① to step ⑦, the system transmission ratio is calculated based on the transmission ratio when the system is operating in power split mode, that is, it all satisfies this fixed relationship:

[0118] ω shaft =ω wheel k shaft ..........................................(36)

[0119] ω mot =ω shaft (1+k p2 )............................................(37)

[0120]

[0121] ω gen =(1+k) p1 )ω eng (i,j)-k p1 ω shaft ...................(39)

[0122]

[0123] ω eng =g(T) eng (41)

[0124] Then there must exist a definite function λ(k) such that when J(k) reaches its minimum value, T eng (k)=T eng (i).

[0125] Let the value of λ(k) be denoted as λ(t). Then λ(t) is the optimal equivalent factor for the current driving condition as it changes over time.

[0126] ⑧ Repeat steps ① to ⑦ to obtain the optimal equivalent factor λ for each of the following working conditions. i (t).

[0127] (2) Obtain neural network models corresponding to different working conditions.

[0128] ① The optimal equivalent factor λ for the change of working condition i over time obtained from the above offline optimization. i (t) is the vehicle speed v as a function of time for condition i. i (t), vehicle absolute acceleration a i (t), SOC of power battery i (t), Target torque T at the output shaft reqi Using (t) as input, construct the optimal equivalent factor dataset for working condition i, and use this dataset to train the neural network to form the optimal equivalent factor matching model based on the neural network under working condition i.

[0129] ② A backpropagation neural network was used for training. The neural network consists of an input layer, two hidden layers, and an output layer. The number of nodes in the input layer is 5, and the number of nodes in the output layer is 1. The number of iterations is 200. The Levenberg-Marquardt algorithm was used to solve the problem. The tansig transfer function was used for the hidden layer, and the purelin transfer function was used for the neurons in the output layer.

[0130] ③ Repeat steps ① to ② to train the optimal equivalent factor matching model for each of the driving conditions. The trained model can, under a given driving condition, determine the vehicle speed v at the current moment. i (t), vehicle absolute acceleration a i (t), SOC of power battery i (t), Target torque T at the output shaft reqi (t), matching the optimal equivalent factor in real time.

[0131] In addition, based on the optimal equivalent factor λ and the accelerator pedal travel C f The specific method for calculating the optimal torque distribution ratio of gasoline compression ignition engine 1, generator 2, and electric motor 3, based on the boundary conditions of the operating conditions of the gasoline compression ignition engine and the objective function of the energy consumption minimization control strategy, is as follows:

[0132] When the vehicle is running in power-split mode:

[0133] The Hamiltonian function H for establishing the energy minimization (ECMS) control strategy is as follows:

[0134] H = m fuel +m bat .........................................(42)

[0135] In the formula, the objective function is set as the instantaneous fuel consumption m of the gasoline compression ignition (GCI) engine. fuel The state variable is set as the instantaneous equivalent fuel consumption of the battery, m. bat According to the definition of the Hamiltonian function, the cost expression for the Equivalent Energy Minimization (ECMS) control strategy can be obtained as follows:

[0136] J = m fuel +λP bat ..........................................(43)

[0137] In the formula, J represents the instantaneous minimum cost of equivalent energy consumption, and m fuel P represents the instantaneous fuel consumption of a gasoline compression ignition (GCI) engine, λ is the optimal equivalent factor at the current moment, and P is the instantaneous fuel consumption of the engine. bat This represents the total battery power. Among them:

[0138] m fuel =f[ω eng ,T eng ]....................................(44)

[0139] ω eng =g(T) eng )............................................(45)

[0140] P bat =η bat (P mot -P gen )................................(46)

[0141] P mot =Φ(ω) mot T mot )......................................(47)

[0142] P gen =Ψ(ω) gen T gen)...................................(48)

[0143] ω shaft =ω wheel k shaft ...................................(49)

[0144] ω mot =ω shaft (1+k p2 (50)

[0145]

[0146] ω gen =(1+k) p1 )ω eng -k p1 ω shaft ....................(52)

[0147]

[0148] In the formula, f[ω eng ,T eng [T] represents the functional relationship between fuel consumption and engine speed / torque of a gasoline compression ignition engine, obtained from the difference in the universal characteristic MAP of the gasoline compression ignition engine; eng For the output torque of a gasoline compression ignition engine; ω eng For gasoline compression ignition engines with torque T eng The engine speed corresponding to the optimal fuel consumption condition during operation is obtained from the MAP difference of the universal characteristic of the gasoline compression ignition engine, and its functional relationship is expressed by g(T). eng ) indicates; P bat For power battery power; η bat For the charging and discharging efficiency of the power battery; P mot P represents the power of the electric motor. gen The generator power is the power of the motor and generator. When the power of the motor and generator is positive, it consumes electrical energy; when the power is negative, it generates electrical energy. ω mot T represents the motor speed. mot ω represents the motor torque. gen T is the generator speed; gen ω represents the generator torque. shaft k is the angular velocity at the output shaft. shaft T is the gear ratio of the final drive located between the rear wheels and the output shaft; req (i) represents the target torque at the output shaft; Φ(ω) mot Tmot Ψ(ω) represents the functional relationship between motor power, motor speed, and motor torque, obtained from the difference in the motor's operating characteristics (MAP); gen T gen The expression indicates that the functional relationship between generator power, generator speed, and torque is obtained from the difference in generator operating characteristics (MAP).

[0149] Because the optimal equivalent factor λ; η bat k shaft k p1 k p2 Determined by the system's inherent properties; other parameters can be determined by T. eng It is derived that the unique variable T can be... eng As the sole control variable, the discretized control objective is: minJ = h(T) eng ).

[0150] The constraints satisfy:

[0151]

[0152] P eng ∈P GCI ...........................................(55)

[0153] ω eng ∈ω GCI .........................................(56)

[0154] T eng ∈T GCI ...........................................(57)

[0155] h(T eng ) represents T eng The functional relationship between the instantaneous minimum cost J of equivalent energy consumption and energy consumption; (.) min and(.) max P represents the minimum and maximum values, respectively; bat Indicates battery power; P GCI ω GCI and T GCI These represent the power, speed, and torque ranges within which a gasoline compression ignition engine can achieve stable combustion and low raw emissions.

[0156] The optimal output torque T of the gasoline compression ignition engine at that moment was determined through the above process. eng Then, the generator torque T can be obtained.gen Motor torque T mot :

[0157]

[0158]

[0159] This torque distribution strategy minimizes the instantaneous cost of equivalent energy consumption under constraints such as engine external characteristics, motor external characteristics, and the unique operating conditions of gasoline compression ignition engines. When the system operates in power-split mode, this torque distribution strategy controls the output torque of the engine, generator, and electric motor. This avoids the unstable and rough operating conditions of gasoline compression ignition engines while meeting the vehicle's required drive torque, thus optimizing the vehicle's economy.

[0160] In some exemplary embodiments, reference is made to Figure 1 Controlling the vehicle to execute the power split mode also includes controlling the vehicle to execute the engine start mode before closing the engine clutch 11. Controlling the vehicle to execute the engine start mode includes closing the engine lock-up clutch 12, disengaging the generator lock-up clutch 21, disengaging the engine clutch 11, and disengaging the electric motor clutch 31, so that the generator 2 outputs torque T for starting the gasoline compression ignition engine 1. gs The gasoline compression ignition engine 1 is driven by the first planetary gear 4 to rotate to the minimum speed n, which is the speed at which the gasoline compression ignition engine achieves stable combustion and low initial emissions. ed Disengage the engine lock-up clutch 12 and engage the engine clutch 11, allowing the gasoline compression ignition engine 1 to output torque through the output shaft 7. This process should be completed within 0.2 seconds, ensuring that the gasoline compression ignition engine 1 avoids unstable and rough operating conditions during startup.

[0161] It should be noted that in this embodiment, the vehicle is running in engine start mode:

[0162] Before fuel injection in a gasoline compression ignition engine, the generator outputs a torque T for starting the engine. gs The gasoline compression ignition engine is not working; the generator is used to drive the vehicle.

[0163] T gen =T gs .....................................(60)

[0164] T eng =0.......................................(61)

[0165]

[0166] The engine speed of the gasoline compression ignition engine is dragged down to the lower limit of the speed range n, which is conducive to stable combustion and low primary emissions in gasoline compression ignition engines. ed Then, the gasoline compression ignition engine begins to inject fuel and ignite to output torque:

[0167]

[0168] In the formula, T ed This represents the lower limit of the torque range for stable combustion and low initial emissions in gasoline compression ignition engines.

[0169] After the gasoline compression ignition engine starts successfully, the generator outputs torque as follows:

[0170]

[0171] Motor output torque:

[0172]

[0173] The entire gasoline compression ignition engine start-up process is completed within 0.2 seconds, after which the system switches to other operating modes.

[0174] In some exemplary embodiments, controlling the vehicle to execute a pure electric drive mode includes disengaging the engine clutch 11, engaging the electric motor clutch 31, engaging the engine lock-up clutch 12, and disengaging the electric motor lock-up clutch 21, thereby stopping the gasoline compression ignition engine 1 and driving the output shaft 7 to rotate via the second planetary gear 5, thereby driving the wheels to rotate.

[0175] It should be noted that in this embodiment, the vehicle operates in pure electric drive mode:

[0176] The gasoline compression ignition engine is not working, T eng =0.

[0177] when hour:

[0178]

[0179] T gen =0...........................(67)

[0180] in, This is the maximum output torque of the motor at the current operating speed, obtained by looking up a table using the motor operating characteristics MAP.

[0181] when hour:

[0182]

[0183]

[0184] Controlling the vehicle to execute the engine drive mode includes closing the engine clutch 11, disengaging the electric motor clutch 31, disengaging the engine lock-up clutch 12, and disengaging the generator lock-up clutch 21, causing the electric motor 3 to stop. The gasoline compression ignition engine 1 drives the output shaft 7 to rotate via the first planetary gear 4 to drive the wheels to rotate. The generator 2 outputs negative torque to balance the torque transmitted from the gasoline compression ignition engine 1 to the generator 2 via the first planetary gear 4 and to generate electricity.

[0185] It should be noted that in this embodiment, the vehicle is running in engine mode:

[0186] The motor is not working, T mot =0.

[0187] Gasoline compression ignition engine output torque:

[0188]

[0189] Generator output torque:

[0190]

[0191] Controlling the vehicle to execute the hybrid drive mode includes closing the engine clutch 11, closing the electric motor clutch 31, closing the generator lock-up clutch 21, and disengaging the engine lock-up clutch 12, causing the generator 2 to stop. The gasoline compression ignition engine 1 drives the output shaft 7 to rotate via the first planetary gear 4 and the electric motor 3 via the second planetary gear 5, thereby driving the wheels to rotate.

[0192] It should be noted that in this embodiment, the vehicle operates in a hybrid drive mode:

[0193] The gasoline compression ignition engine achieves its maximum torque T within the stable combustion and low initial emission torque range. eu Running, that is:

[0194] T eng =T eu .........................(72)

[0195] The generator does not output torque

[0196] T gen =0.........................(73)

[0197] Motor output torque T mot for:

[0198]

[0199] The advantage of hybrid drive mode over power split mode is that, in gasoline compression ignition engines, the ω-mode power split mode provides a more efficient and efficient driving experience. eng1 :

[0200]

[0201] Reduce to ω eng2 :

[0202]

[0203] Because ω gen >0, so ω eng2 <ω eng1 In hybrid drive mode, the engine will output less power under the same operating conditions by the following amount:

[0204]

[0205] Therefore, it can be seen that, compared with the power split mode, the hybrid drive mode allows the gasoline compression ignition engine to achieve a maximum torque T within the torque range that meets the requirements of stable combustion and low initial emissions. eu Under the constraints, it outputs higher power, which has a greater advantage over the power split mode when the vehicle is operating under heavy load conditions.

[0206] In some exemplary embodiments, reference is made to Figure 1 During the braking mode, the electric motor clutch 31 is closed, the engine clutch 11 is disengaged, the engine lock-up clutch 12 is disengaged, and the generator lock-up clutch 21 is disengaged, causing the gasoline compression ignition engine 1 to stop and the generator 2 to stop. The electric motor 3 outputs negative torque to cooperate with the vehicle's brake pads for braking and recovers some of the energy during the braking process.

[0207] It should be noted that in this embodiment, the vehicle is running in braking mode:

[0208] The electric motor outputs negative torque to recover braking energy.

[0209]

[0210]

[0211] In the formula, T brake To provide the required braking torque at the output shaft, C is the vehicle's maximum braking torque. b For the normalized brake pedal travel, C b =1 represents the brake pedal reaching its maximum travel, C b=0 means the brake pedal is not depressed.

[0212] like The remaining braking torque is then provided by the mechanical brake.

[0213] Gasoline compression ignition engine shutdown:

[0214] T eng =0.......................................(80)

[0215] The generator is not outputting torque:

[0216] T gen =0........................................(81)

[0217] Furthermore, a vehicle model was built using the Simulink platform, and a control strategy was developed using the Matlab platform. For the C-WTVC test condition (transient operating condition of Chinese heavy-duty commercial vehicles), the control method of this invention and a traditional control method were used to perform performance simulations on a hybrid system using a gasoline compression ignition engine. The simulation results are as follows:

[0218] Figure 5 This is a diagram showing the operating characteristics of a gasoline compression ignition engine using traditional control methods.

[0219] like Figure 5 As shown, during the entire test cycle, the gasoline compression ignition engine operated in the high-efficiency range for 31% of the time, was in a shutdown state for 43% of the time, and operated under conditions where the gasoline compression ignition engine was difficult to operate stably or under rough operating conditions for a considerable period of time.

[0220] Figure 6 This is a diagram showing the operating characteristics of a gasoline compression ignition engine using the control method of this invention.

[0221] like Figure 6 As shown, the gasoline compression ignition engine operated in the high-efficiency zone for 33% of the time and was in a shutdown state for 66% of the time during the entire test cycle. The operating characteristics of the gasoline compression ignition engine did not go through the operating conditions that make it difficult for gasoline compression ignition engines to operate stably or operate roughly, and effectively avoided the low-load, low-efficiency operating conditions.

[0222] Figure 7 It is the vehicle speed following curve under the control method of the present invention.

[0223] like Figure 7 As shown, the control method of the present invention can meet the power requirements of the vehicle and achieve speed following.

[0224] Figure 8 It is the engine start-stop curve of the vehicle under the control method of the present invention; Figure 9 This is a comparison diagram of the operating condition distribution of a gasoline compression ignition engine using the control method of this invention and using a conventional control method.

[0225] like Figure 8 As shown, under the control of the method of the present invention, the gasoline compression ignition engine cycles 15 times. This control method can effectively achieve engine start-stop control and avoid frequent start-stop cycles; combined with Figure 9 It is evident that the control method of the present invention can effectively increase the proportion of time that the gasoline compression ignition engine operates in the high-efficiency range, reduce the proportion of time that the gasoline compression ignition engine operates under low-load and low-efficiency conditions, and effectively prevent the gasoline compression ignition engine from operating under conditions where it is difficult to operate stably or under rough operating conditions.

[0226] Figure 10 This is a graph showing the change in battery charge during cycling under the control method of this invention and under the conventional control method. Figure 11 This is a graph showing the change in cyclic fuel consumption under the control method of this invention and under the conventional control method.

[0227] like Figure 10-11 As shown, in urban operating conditions, the power consumption of the control method of this invention is higher than that of the traditional control method, while the fuel consumption is lower. This indicates that the motor assist torque of the dynamic programming simulation strategy at this stage is greater than that of the empirical rule-based control strategy, resulting in a longer engine downtime. The difference in power consumption is compensated by recovering as much braking energy as possible during the final deceleration phase, thus reducing the overall vehicle fuel consumption. As shown in Table 1, both control methods can achieve battery cycle balance. The fuel consumption per 100 kilometers of the control method of this invention is 8.77 lower than that of the traditional control method. Therefore, the control method of this invention can improve the overall energy efficiency of the system while avoiding the operation of the gasoline compression ignition engine under unstable or rough operating conditions.

[0228] Table 1 Comparison of vehicle fuel consumption per 100 kilometers and power battery power consumption data

[0229]

[0230] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hybrid power system for a gasoline compression ignition engine in a vehicle, comprising: Gasoline compression ignition engine (1); Generator (2); Electric motor (3); The first planetary gear (4) is connected to the gasoline compression ignition engine (1) and the generator (2) respectively; The second planetary gear (5) is mounted on the vehicle frame (6) and connected to the electric motor (3); The output shaft (7) is connected to the first planetary gear (4) and the second planetary gear (5), and extends from the second planetary gear (5) to be connected to the wheels of the vehicle via a reducer; The engine clutch (11) is connected to the gasoline compression ignition engine (1) and the first planetary gear (4), respectively; The electric motor clutch (31) is connected to the electric motor (3) and the second planetary gear (5) respectively; An engine lock-up clutch (12) is connected to the gasoline compression ignition engine (1) and the vehicle frame (6), respectively. as well as The generator lock-up clutch (21) is connected to the generator (2) and the vehicle frame (6) respectively; The driving mode of the vehicle is switched by controlling the engine clutch (11), the electric motor clutch (31), the engine lock-up clutch (12) and the generator lock-up clutch (21) to close or disengage, thereby changing the transmission relationship between the gasoline compression ignition engine (1), the generator (2) and the electric motor (3) and the output shaft (7).

2. The hybrid power system for a gasoline compression ignition engine in a vehicle according to claim 1, wherein, The first planetary gear (4) includes: The first planetary carrier (41) is connected to the gasoline compression ignition engine (1); The first sun gear (42) meshes with the first planet gear (44) mounted on the first planet carrier (41) and is connected to the generator (2); and The first gear ring (43) meshes with the first planetary gear (44) mounted on the first planetary carrier (41) and is connected to the first end (71) of the output shaft (7); The engine clutch (11) is located between the gasoline compression ignition engine (1) and the first planetary carrier (41) to control the connection or disconnection of the gasoline compression ignition engine (1) and the first planetary carrier (41). When the gasoline compression ignition engine (1) is connected to the first planetary carrier (41), the gasoline compression ignition engine (1) drives the first planetary carrier (41), the first ring gear (43), the first sun gear (42) and the output shaft (7) to rotate, and the first sun gear (42) drives the generator (2) to generate electricity.

3. The hybrid power system for a gasoline compression ignition engine in a vehicle according to claim 2, wherein, The second planetary gear (5) includes: The second sun gear (51) is connected to the electric motor (3); A second planetary carrier (52) is connected to the output shaft (7) such that a second planetary gear (54) mounted on the second planetary carrier (52) meshes with the second sun gear (51), and a second end (72) of the output shaft (7) extends from the second planetary carrier (52); and The second gear ring (53) is mounted on the vehicle frame (6) and meshes with the second planetary gear (54) mounted on the second planetary carrier (52); The motor clutch (31) is disposed between the motor (3) and the second sun gear (51) to control the connection or disconnection of the motor (3) and the second sun gear (51), so that when the motor (3) is connected to the second sun gear (51), the motor (3) drives the second sun gear (51), the second planetary carrier (52), and the output shaft (7) to rotate.

4. A control method for a hybrid power system of a gasoline compression ignition engine for a vehicle according to any one of claims 1-3, comprising: Obtain the vehicle's brake pedal travel C b ; If the brake pedal travel C b If the value is >0, then the vehicle will be controlled to perform braking mode; If the brake pedal travel C b =0, then obtain the accelerator pedal travel C. f And determine the vehicle's current target torque T. req ;as well as According to the target torque T req Based on the relationship between the torque range at the output shaft (7) and the vehicle's torque range when operating in power split mode, determine the type of drive mode that the vehicle needs to execute at the moment. Wherein, the target torque T req The accelerator pedal travel C f The product of the maximum torque required by the vehicle at the current speed.

5. The control method according to claim 4, wherein, If the target torque T req Less than the minimum torque T at the output shaft (7) when the vehicle is running in power-split mode. reqd Then obtain the current SOC of the power battery. act ; If the current power battery charge SOC act The state of charge (SOC) of the power battery is greater than the low charge threshold. low Then the vehicle will be controlled to operate in pure electric drive mode; If the current power battery charge SOC act Less than the low charge threshold SOC of the power battery low Then the vehicle will be controlled to execute the engine drive mode; If the target torque T req The torque at the output shaft (7) is greater than the maximum value T of the torque when the vehicle is running in power-split mode. requ Then the vehicle will be controlled to execute a hybrid drive mode; as well as If the target torque T req The minimum torque T at the output shaft (7) when the vehicle is running in power-split mode. reqd With the maximum value T requ Between these, the vehicle is controlled to execute a power split mode.

6. The control method according to claim 5, wherein, The control of the vehicle to perform power splitting mode includes: Close the engine clutch (11), close the electric motor clutch (31), disengage the engine lock-up clutch (12), and disengage the generator lock-up clutch (21), so that the gasoline compression ignition engine (1) drives the output shaft (7) to rotate via the first planetary gear (4), and the generator (2) outputs negative torque to balance the torque transmitted from the gasoline compression ignition engine (1) to the generator (2) via the first planetary gear (4) and generate electricity, and the electric motor (3) drives the output shaft (7) to rotate via the second planetary gear (5).

7. The control method according to claim 6, wherein, The control of the vehicle to perform power split mode also includes: Based on the road conditions, obtain the average vehicle speed v over 30 seconds during the vehicle's journey. avg Average acceleration a avg And the ratio of idling time to r i ; The average vehicle speed v avg The average acceleration a avg And the idle time ratio r i Input to the fuzzy controller, output the current operating condition category of the vehicle; Get the vehicle's current speed v i (t), absolute acceleration a i (t) and the SOC of the power battery i (t); The working condition category and the vehicle speed v i (t), the absolute acceleration a i (t), the SOC of the power battery i (t) and the target torque T req Input the optimal equivalent factor neural network model corresponding to the stated working condition category, and output the optimal equivalent factor λ; and Based on the optimal equivalent factor λ and the accelerator pedal travel C f The optimal torque distribution ratio of the gasoline compression ignition engine (1), the generator (2), and the electric motor (3) is calculated by using the energy consumption minimization control strategy objective function based on the operating boundary conditions of the gasoline compression ignition engine.

8. The control method according to claim 6, wherein, The control of the vehicle to perform power split mode also includes: Before disengaging the engine clutch (11), the vehicle is controlled to execute an engine start mode, including: Close the engine lock-up clutch (12), disengage the generator lock-up clutch (21), disengage the engine clutch (11), and disengage the electric motor clutch (31), so that the generator (2) outputs torque T for starting the gasoline compression ignition engine (1). gs The gasoline compression ignition engine (1) is driven by the first planetary gear (4) to rotate to the minimum speed n, which is the speed at which the gasoline compression ignition engine achieves stable combustion and low initial emissions. ed ;as well as Disengage the engine lock-up clutch (12) and close the engine clutch (11) so that the gasoline compression ignition engine (1) outputs torque through the output shaft (7).

9. The control method according to claim 5, wherein, The control of the vehicle to execute pure electric drive mode includes: Disengage the engine clutch (11), engage the electric motor clutch (31), engage the engine lock-up clutch (12), disengage the generator lock-up clutch (21), thereby stopping the gasoline compression ignition engine (1). The electric motor (3) drives the output shaft (7) to rotate via the second planetary gear (5), thereby driving the wheels to rotate; and / or, The control of the vehicle to execute the engine drive mode includes: Close the engine clutch (11), disengage the electric motor clutch (31), disengage the engine lock-up clutch (12), and disengage the generator lock-up clutch (21), causing the electric motor (3) to stop. The gasoline compression ignition engine (1) drives the output shaft (7) to rotate via the first planetary gear (4) to drive the wheels to rotate. The generator (2) outputs a negative torque to balance the torque transmitted from the gasoline compression ignition engine (1) to the generator (2) via the first planetary gear (4) and generates electricity; and / or, The control of the vehicle to execute the hybrid drive mode includes: Close the engine clutch (11), close the electric motor clutch (31), close the generator lock-up clutch (21), and disengage the engine lock-up clutch (12) to stop the generator (2). The gasoline compression ignition engine (1) drives the output shaft (7) to rotate via the first planetary gear (4) and the electric motor (3) via the second planetary gear (5) to drive the wheels to rotate.

10. According to the control method of claim 4, during the execution of the braking mode, the electric motor clutch (31) is closed, the engine clutch (11) is disengaged, the engine lock-up clutch (12) is disengaged, and the generator lock-up clutch (21) is disengaged, so that the gasoline compression ignition engine (1) stops, the generator (2) stops, the electric motor (3) outputs negative torque to cooperate with the vehicle's brake pads for braking, and recovers part of the energy during the braking process.

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