A control method and system for a hybrid vehicle

Abstract

The present invention provides a control method and system for a hybrid vehicle, the method comprising: obtaining vehicle operation data of the hybrid vehicle when the hybrid vehicle is running, the vehicle operation data including at least vehicle speed, slope, SOC and throttle opening; judging whether the hybrid vehicle is in a coasting state based on the vehicle operation data; and controlling the hybrid vehicle to maintain the current gear or switch back to a neutral gear according to the vehicle speed, SOC and slope when the hybrid vehicle is in a coasting state. In this solution, when it is determined that the hybrid vehicle is in a coasting state, the hybrid vehicle is controlled to maintain the current gear or switch back to a neutral gear according to the vehicle speed, SOC and slope, thereby reducing fuel consumption in the entire driving cycle and meeting the power demand of the entire vehicle, avoiding excessive engine reverse drag time, reducing the energy consumption of the entire vehicle and improving the thermal management effect of the engine.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and in particular to a control method and system for a hybrid electric vehicle. Background Art

[0002] When a hybrid vehicle is coasting, the current control strategy used is: the hybrid vehicle maintains the current gear while coasting, and then the motor recovers energy at its maximum capacity.

[0003] However, when the "sliding resistance is too large and the throttle needs to intervene in advance", the above control strategy requires the kinetic energy generated by the combustion of fuel in the whole vehicle to reverse the engine and generate electricity for the motor. This increases the fuel consumption of the whole vehicle and the long reverse dragging time of the engine reduces the overall temperature of the engine. The energy consumption of the whole vehicle is high and the thermal management effect of the engine is poor. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a control method and system for a hybrid electric vehicle to solve the problems of high vehicle energy consumption and poor thermal management effect on the engine in existing control strategies for hybrid electric vehicles.

[0005] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0006] A first aspect of an embodiment of the present invention discloses a control method for a hybrid electric vehicle, the method comprising:

[0007] When the hybrid vehicle is running, obtaining vehicle operation data of the hybrid vehicle, the vehicle operation data at least including vehicle speed, slope, battery state of charge SOC and throttle opening;

[0008] Based on the vehicle operation data, determining whether the hybrid vehicle is in a coasting state;

[0009] When the hybrid electric vehicle is in a coasting state, the hybrid electric vehicle is controlled to maintain a current gear position or switch back to a neutral gear position according to the vehicle speed, the SOC and the slope.

[0010] Preferably, controlling the hybrid electric vehicle to maintain the current gear or switch back to the neutral gear according to the vehicle speed, the SOC and the slope comprises:

[0011] determining whether the vehicle speed is greater than or equal to a first vehicle speed threshold;

[0012] If the vehicle speed is greater than or equal to a first vehicle speed threshold, controlling the hybrid vehicle to maintain a current gear position;

[0013] If the vehicle speed is less than the first vehicle speed threshold, determining whether the SOC is within a preset SOC range, the preset SOC range being composed of a first SOC threshold and a second SOC threshold, the first SOC threshold being greater than the second SOC threshold;

[0014] If the SOC is not within the preset SOC range, controlling the hybrid electric vehicle to maintain the current gear position, or controlling the hybrid electric vehicle to switch back to the neutral gear position after a delay of a set time;

[0015] If the SOC is within the preset SOC range, determining whether the road condition on which the hybrid electric vehicle is running is a downhill road condition based on the slope;

[0016] If the road condition on which the hybrid electric vehicle is running is not a downhill road condition, controlling the hybrid electric vehicle to switch back to the neutral position after a delay of a set time;

[0017] If the road condition on which the hybrid electric vehicle is running is a downhill road condition, based on the set time and the vehicle speed, the hybrid electric vehicle is controlled to maintain the current gear position or switch back to the neutral gear position.

[0018] Preferably, if the SOC is not within the preset SOC range, controlling the hybrid electric vehicle to maintain the current gear, or controlling the hybrid electric vehicle to switch back to the neutral gear after a delay of a set time, comprises:

[0019] When the SOC is greater than or equal to the first SOC threshold, controlling the hybrid electric vehicle to switch back to the neutral position after a delay of a set time;

[0020] When the SOC is less than or equal to the second SOC threshold, the hybrid vehicle is controlled to maintain the current gear.

[0021] Preferably, if the road condition on which the hybrid electric vehicle is running is a downhill road condition, based on the set time and the vehicle speed, controlling the hybrid electric vehicle to maintain the current gear or switch back to the neutral gear comprises:

[0022] If the road condition on which the hybrid electric vehicle is running is a downhill road condition, calculating the speed change amplitude of the vehicle within the set time;

[0023] When the vehicle speed variation range is within a preset variation range, or when the vehicle speed variation range is greater than a maximum value of the variation range, controlling the hybrid vehicle to maintain a current gear position;

[0024] When the vehicle speed variation is less than the minimum value of the variation range, the hybrid vehicle is controlled to switch back to the neutral position after the set time has elapsed.

[0025] Preferably, judging whether the hybrid electric vehicle is in a coasting state based on the vehicle operation data includes:

[0026] Based on the vehicle operation data, obtaining a first duration during which the vehicle speed is continuously higher than a second vehicle speed threshold, and obtaining a second duration during which the throttle opening is continuously 0;

[0027] When the first duration and the second duration are both greater than a duration threshold, it is determined that the hybrid vehicle is in a coasting state.

[0028] A second aspect of an embodiment of the present invention discloses a control system for a hybrid vehicle, the system comprising:

[0029] An acquisition unit, used for acquiring vehicle operation data of the hybrid vehicle when the hybrid vehicle is running, wherein the vehicle operation data at least includes vehicle speed, slope, battery state of charge SOC and throttle opening;

[0030] a judgment unit, configured to judge whether the hybrid electric vehicle is in a coasting state based on the vehicle operation data;

[0031] The control unit is used to control the hybrid vehicle to maintain the current gear or switch back to the neutral gear according to the vehicle speed, the SOC and the slope when the hybrid vehicle is in a coasting state.

[0032] Preferably, the control unit comprises:

[0033] A first judging module, used to judge whether the vehicle speed is greater than or equal to a first vehicle speed threshold;

[0034] A first control module, configured to control the hybrid electric vehicle to maintain a current gear if the vehicle speed is greater than or equal to a first vehicle speed threshold;

[0035] A second judgment module is used to judge whether the SOC is within a preset SOC range if the vehicle speed is less than the first vehicle speed threshold, the preset SOC range being composed of a first SOC threshold and a second SOC threshold, and the first SOC threshold is greater than the second SOC threshold;

[0036] A second control module is used to control the hybrid electric vehicle to maintain the current gear position if the SOC is not within the preset SOC range, or to control the hybrid electric vehicle to switch back to the neutral gear position after a delay of a set time;

[0037] A third judgment module is used to judge whether the road condition on which the hybrid electric vehicle is running is a downhill road condition based on the slope if the SOC is within the preset SOC range;

[0038] A third control module, configured to control the hybrid vehicle to switch back to a neutral position after a delay of a set time if the road condition on which the hybrid vehicle is running is not a downhill road condition;

[0039] The fourth control module is used to control the hybrid vehicle to maintain the current gear or switch back to the neutral gear based on the set time and the vehicle speed if the road condition on which the hybrid vehicle is running is a downhill road condition.

[0040] Preferably, the second control module is specifically used to: when the SOC is greater than or equal to the first SOC threshold, control the hybrid electric vehicle to switch back to the neutral gear after a set delay time; when the SOC is less than or equal to the second SOC threshold, control the hybrid electric vehicle to maintain the current gear.

[0041] Preferably, the fourth control module is specifically used to: if the road condition on which the hybrid electric vehicle is running is a downhill road condition, calculate the speed change amplitude of the vehicle within the set time;

[0042] When the vehicle speed variation range is within a preset variation range, or when the vehicle speed variation range is greater than a maximum value of the variation range, controlling the hybrid vehicle to maintain a current gear position;

[0043] When the vehicle speed variation is less than the minimum value of the variation range, the hybrid vehicle is controlled to switch back to the neutral position after the set time has elapsed.

[0044] Preferably, the judging unit comprises:

[0045] an acquisition module, configured to acquire, based on the vehicle operation data, a first duration during which the vehicle speed is continuously higher than a second vehicle speed threshold, and a second duration during which the throttle opening is continuously 0;

[0046] The determination module is configured to determine that the hybrid electric vehicle is in a coasting state when both the first duration and the second duration are greater than a duration threshold.

[0047] A control method and system for a hybrid vehicle is provided based on the above-mentioned embodiment of the present invention. The method comprises: when the hybrid vehicle is running, obtaining vehicle operation data of the hybrid vehicle, the vehicle operation data at least including vehicle speed, slope, SOC and throttle opening; judging whether the hybrid vehicle is in a coasting state based on the vehicle operation data; when the hybrid vehicle is in a coasting state, controlling the hybrid vehicle to maintain the current gear or switch back to neutral gear according to vehicle speed, SOC and slope. In this scheme, when it is determined that the hybrid vehicle is in a coasting state, controlling the hybrid vehicle to maintain the current gear or switch back to neutral gear according to vehicle speed, SOC and slope reduces fuel consumption in the entire driving cycle and meets the power demand of the whole vehicle, avoids the engine from dragging too long, reduces the energy consumption of the whole vehicle and improves the thermal management effect of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0049] Figure 1 A flow chart of a control method for a hybrid vehicle provided by an embodiment of the present invention;

[0050] Figure 2 A flow chart of controlling a gearbox to maintain a current gear position or switch back to a neutral gear position provided by an embodiment of the present invention;

[0051] Figure 3 Another flow chart of a control method for a hybrid vehicle provided by an embodiment of the present invention;

[0052] Figure 4 A structural block diagram of a control system of a hybrid vehicle provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] In this application, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0055] Before explaining this plan, some terms are explained here to better understand the subsequent explanation content of this plan.

[0056] P1 parallel type: A technical route for hybrid vehicles, whose drive assembly consists of an electronically controlled mechanical automatic transmission (Automated Manual Transmission, referred to as AMT transmission), a motor, a clutch, and an engine. The clutch is located between the AMT transmission and the motor.

[0057] SOC (State of Charge): Battery state of charge, reflecting the remaining capacity of the battery. Its numerical value is defined as the ratio of the remaining battery capacity to the battery capacity, usually expressed as a percentage.

[0058] Electronic accessories: usually refers to components on the vehicle that require external power supply to work.

[0059] Engine thermal management: Measures taken to keep the engine running at an optimum temperature.

[0060] Vehicle energy consumption: the energy consumed by the vehicle during the entire driving cycle, including fuel and motor power.

[0061] As can be seen from the background technology, the current control strategy for hybrid vehicles is: the hybrid vehicle maintains the current gear when coasting, and then the motor recovers energy at its maximum capacity. However, in the case of "the coasting resistance is too large and the throttle needs to intervene in advance", the above control strategy requires the kinetic energy generated by the fuel combustion of the whole vehicle to reverse the engine and generate electricity for the motor, which increases the fuel consumption of the whole vehicle and the engine reverses for too long, which reduces the overall temperature of the engine, resulting in high energy consumption of the whole vehicle and poor thermal management effect on the engine.

[0062] To solve the above problems, an embodiment of the present invention provides a control method and system for a hybrid vehicle. When it is determined that the hybrid vehicle is in a coasting state, the hybrid vehicle is controlled to maintain the current gear or switch back to the neutral gear according to the vehicle speed, SOC and slope, thereby reducing fuel consumption in the entire driving cycle and meeting the power demand of the entire vehicle, avoiding the engine's reverse drag time for too long, reducing the energy consumption of the entire vehicle and improving the thermal management effect of the engine.

[0063] It should be noted that the control method and system of a hybrid vehicle proposed in this solution can be applied to various types of hybrid vehicles such as P1 parallel hybrid vehicles; after applying this solution, when the hybrid vehicle is in a high-speed driving condition and the driver has no throttle demand or brake demand (equivalent to the hybrid vehicle being in a high-speed gliding state), the gearbox, engine, clutch and motor of the hybrid vehicle are controlled accordingly, so as to maximize the reduction of the energy consumption of the whole vehicle during high-speed gliding, and take into account the power demand of the whole vehicle and the driving safety performance. The following is a detailed description of this solution through various embodiments.

[0064] See also Figure 1 , shows a flow chart of a control method for a hybrid electric vehicle provided by an embodiment of the present invention, the control method comprising:

[0065] Step S101: When the hybrid electric vehicle is running, the vehicle operation data of the hybrid electric vehicle is obtained, and the vehicle operation data at least includes vehicle speed, slope, SOC and throttle opening.

[0066] In the process of implementing step S101, the hybrid vehicle to be controlled obtains the current vehicle operation data of the hybrid vehicle in real time during operation. The obtained vehicle operation data includes but is not limited to information such as vehicle speed, slope, SOC (SOC of the power battery), throttle opening (i.e., throttle pedal opening), clutch position and operation mode.

[0067] Step S102: Based on the vehicle operation data, determine whether the hybrid vehicle is in a coasting state. If the hybrid vehicle is in a coasting state, execute step S103; if the hybrid vehicle is not in a coasting state, end.

[0068] In the specific implementation of step S102, the vehicle operation data obtained in real time is used to determine whether the hybrid vehicle is in a gliding state (i.e., whether it is in a high-speed gliding state); if the hybrid vehicle is in a gliding state, step S103 is executed; if the hybrid vehicle is not in a gliding state, the process ends.

[0069] In some embodiments, the specific implementation method of determining whether the hybrid vehicle is in a coasting state is: based on the vehicle operation data, obtaining a first duration during which the vehicle speed is continuously higher than a second vehicle speed threshold (such as 80 km / h), and obtaining a second duration during which the throttle opening is continuously 0; when the first duration and the second duration are both greater than the duration threshold (such as 3s), it is determined that the hybrid vehicle is in a coasting state, and step S103 is executed.

[0070] On the contrary, when the first duration and / or the second duration is not greater than the duration threshold, it is determined that the hybrid vehicle is not in the coasting state, and the process ends.

[0071] That is, using the vehicle operation data of the hybrid vehicle acquired in real time, determining a first duration during which the vehicle speed is continuously higher than the second vehicle speed threshold, and determining a second duration during which the throttle opening is continuously 0;

[0072] Determine whether the first duration and the second duration are greater than a duration threshold;

[0073] When the first duration and the second duration are both greater than the duration threshold, it is determined that the hybrid vehicle is in a coasting state. When the first duration and / or the second duration is not greater than the duration threshold, it is determined that the hybrid vehicle is not in a coasting state.

[0074] In summary, the conditions that need to be met to determine that the hybrid vehicle is in a coasting state are: the first duration for which the vehicle speed is continuously higher than the second vehicle speed threshold is greater than the duration threshold, and the second duration for which the throttle opening is continuously 0 is greater than the duration threshold.

[0075] For example: when the two conditions of "vehicle speed higher than 80km / h" and "accelerator opening is 0" are maintained for more than 3s (duration threshold), it is determined that the hybrid vehicle is in a coasting state.

[0076] Step S103: Control the hybrid vehicle to maintain the current gear or switch back to the neutral gear according to the vehicle speed, SOC and slope.

[0077] In the specific implementation of step S103, when it is determined that the hybrid vehicle to be controlled is in a coasting state, the transmission of the hybrid vehicle is controlled to maintain the current gear, or the transmission is controlled to switch back to the neutral gear, according to the vehicle speed, SOC and slope in the real-time acquired vehicle operation data.

[0078] It should be noted that the specific control logic for controlling the gearbox to maintain the current gear position or switch back to the neutral gear position is detailed in the following embodiments of the present invention. Figure 2 Instructions in .

[0079] In an embodiment of the present invention, when it is determined that the hybrid vehicle is in a coasting state, the hybrid vehicle is controlled to maintain the current gear or switch back to the neutral gear according to the vehicle speed, SOC and slope, thereby reducing fuel consumption in the entire driving cycle and meeting the power demand of the entire vehicle, avoiding the engine's reverse drag time for too long, reducing the energy consumption of the entire vehicle and improving the thermal management effect of the engine.

[0080] For the above-mentioned embodiments of the present invention Figure 1The control of the transmission mentioned in step S103 to maintain the current gear position or switch back to the neutral gear position, see Figure 2 , shows a flow chart of controlling a gearbox to maintain a current gear position or switch back to a neutral gear position provided by an embodiment of the present invention, including the following steps:

[0081] Step S201: Determine whether the vehicle speed is greater than or equal to a first vehicle speed threshold. If the vehicle speed is greater than or equal to the first vehicle speed threshold, execute step S202; if the vehicle speed is less than the first vehicle speed threshold, execute step S203.

[0082] In the specific implementation of step S201, it is determined whether the speed of the hybrid vehicle is greater than or equal to the first speed threshold; if the speed of the hybrid vehicle is greater than or equal to the first speed threshold, step S202 is executed; if the speed of the hybrid vehicle is less than the first speed threshold, step S203 is executed.

[0083] It should be noted that the first vehicle speed threshold can be set according to the type of the hybrid vehicle. For example, assuming that the hybrid vehicle is a heavy-duty tractor, the first vehicle speed threshold is set to 90 km / h; if the speed of the hybrid vehicle is greater than or equal to 90 km / h, execute step S202; if the speed of the hybrid vehicle is less than 90 km / h, execute step S203.

[0084] Step S202: Control the hybrid electric vehicle to maintain the current gear.

[0085] In the process of implementing step S202, if the speed of the hybrid vehicle is greater than or equal to the first speed threshold, the gearbox of the hybrid vehicle is controlled to maintain the current gear. While maintaining the current gear, a torque demand is sent to the motor of the hybrid vehicle to control the motor to recover energy with negative torque (the motor torque for energy recovery is between the rated torque and the peak torque), so that the resistance borne by the hybrid vehicle as a whole is increased. The increased resistance is the "reverse torque of the engine and the energy recovery torque of the motor", which can reduce the speed and acceleration of the hybrid vehicle, thereby ensuring driving safety.

[0086] That is to say, when the hybrid vehicle is in a gliding state and the vehicle speed is greater than or equal to a first speed threshold, the hybrid vehicle's gearbox maintains the current gear and controls the motor to recover energy with negative torque. The aforementioned process is equivalent to the hybrid vehicle shifting into gear to recover energy. At this time, the resistance borne by the entire hybrid vehicle increases with "the engine's reverse torque and the motor's energy recovery torque", which can reduce the speed and acceleration of the hybrid vehicle, thereby ensuring driving safety.

[0087] Step S203: Determine whether the SOC is within the preset SOC range. If the SOC is not within the preset SOC range, execute step S204; if the SOC is within the preset SOC range, execute step S205.

[0088] It should be noted that the preset SOC range is composed of a first SOC threshold and a second SOC threshold, and the first SOC threshold is greater than the second SOC threshold. For example, the first SOC threshold is set to 90%, and the second SOC threshold is set to 40%.

[0089] In the specific implementation of step S203, if the speed of the hybrid vehicle is less than the first speed threshold, it is determined whether the SOC of the power battery of the hybrid vehicle is within the preset SOC range. If the SOC is not within the preset SOC range, step S204 is executed; if the SOC is within the preset SOC range, step S205 is executed.

[0090] Step S204: controlling the hybrid electric vehicle to maintain the current gear position, or controlling the hybrid electric vehicle to switch back to the neutral gear position after a set delay.

[0091] In the specific implementation of step S204, if the SOC of the power battery of the hybrid vehicle is not within the preset SOC range, the transmission of the hybrid vehicle is controlled to maintain the current gear, or the transmission of the hybrid vehicle is controlled to switch back to the neutral gear after a set delay.

[0092] It can be understood that, from the content of the above step S203, it can be seen that the preset SOC range is composed of a first SOC threshold and a second SOC threshold, and the first SOC threshold is greater than the second SOC threshold;

[0093] Then, “SOC is not within the preset SOC range” is divided into the following two situations: SOC is greater than or equal to the first SOC threshold, and SOC is less than or equal to the second SOC threshold.

[0094] In some embodiments, when the SOC is greater than or equal to a first SOC threshold, the hybrid vehicle is controlled to switch back to the neutral position after a delay of a set time, and the set time may be set to 3s.

[0095] Specifically, when the SOC is greater than or equal to the first SOC threshold (one of the situations in which the SOC is not within the preset SOC range), it indicates that the power battery of the hybrid vehicle is nearly fully charged and does not need to be charged. In order to reduce the driving resistance of the entire hybrid vehicle, the gearbox of the hybrid vehicle is controlled to switch back to the neutral position after a delay of a "set time", the clutch of the hybrid vehicle is disengaged, the engine of the hybrid vehicle is idling, and the motor of the hybrid vehicle is not working.

[0096] When the SOC is less than or equal to a second SOC threshold, the transmission of the hybrid vehicle is controlled to maintain the current gear.

[0097] Specifically, when the SOC is less than or equal to a second SOC threshold (another situation in which the SOC is not within the preset SOC range), it indicates that the power battery of the hybrid vehicle is low on power. In order to ensure the operation of the electronic accessories of the hybrid vehicle, the gearbox of the hybrid vehicle is controlled to maintain the current gear, the engine of the hybrid vehicle does not spray fuel, and the motor of the hybrid vehicle recovers energy with negative torque to charge the power battery.

[0098] Step S205: Based on the slope, determine whether the road condition on which the hybrid vehicle is running is a downhill road condition. If the road condition on which the hybrid vehicle is running is not a downhill road condition, execute step S206; if the road condition on which the hybrid vehicle is running is a downhill road condition, execute step S207.

[0099] In the specific implementation of step S205, if the SOC of the power battery of the hybrid vehicle is within a preset SOC range (the SOC is between a first SOC threshold and a second SOC threshold), based on the slope collected in real time during the operation of the hybrid vehicle, it is determined whether the road condition on which the hybrid vehicle is running is a downhill road condition.

[0100] If the road condition on which the hybrid electric vehicle is running is not a downhill road condition (equivalent to the road condition on which the hybrid electric vehicle is currently running being an uphill road condition or a flat road condition), executing step S206;

[0101] If the road condition on which the hybrid electric vehicle is running is a downhill road condition, step S207 is executed.

[0102] Step S206: Control the hybrid vehicle to switch back to the neutral position after a set delay time.

[0103] In the specific implementation of step S206, if the road condition on which the hybrid vehicle is running is not a downhill condition (equivalent to the hybrid vehicle currently running on an uphill or flat road condition), in order to reduce the driving resistance of the hybrid vehicle, the gearbox of the hybrid vehicle is controlled to switch back to the neutral position after a set delay time, and the clutch of the hybrid vehicle is disengaged, the engine is idling, and the motor is not working.

[0104] That is to say, within the set time, if it is determined that the hybrid vehicle is currently running on an uphill road condition or a flat road condition, the hybrid vehicle's gearbox is controlled to switch back to neutral, the hybrid vehicle's clutch is disengaged, the engine is idling, and the motor is not working.

[0105] Step S207: Based on the set time and vehicle speed, control the hybrid vehicle to maintain the current gear or switch back to the neutral gear.

[0106] In the specific implementation of step S207, if the road condition on which the hybrid vehicle is running is a downhill road condition, the transmission of the hybrid vehicle is controlled to maintain the current gear or switch back to the neutral gear according to the vehicle speed within a set time.

[0107] In some embodiments, the specific implementation method of controlling the transmission of the hybrid vehicle to maintain the current gear or switch back to the neutral gear according to the vehicle speed within a set time is:

[0108] If the road condition on which the hybrid vehicle is running is a downhill road condition, the speed change amplitude of the vehicle within a set time is calculated. Specifically, the speed change amplitude of the hybrid vehicle within the set time (also called the speed state change value) is calculated using formula (1).

[0109] Vehicle speed change = (vehicle speed at time t1 - vehicle speed at time t0) / (t1 - t0) (1);

[0110] It should be noted that time t0 is the starting time for calculating the vehicle speed change amplitude, time t1 is the sampling delay time, and time t0 and time t1 are times within the set time.

[0111] After the speed variation range of the hybrid vehicle within the set time is calculated by the above formula (1), when the speed variation range is within a preset variation range, or when the speed variation range is greater than a maximum value of the variation range (equivalent to the speed variation range being greater than the variation range), the gearbox of the hybrid vehicle is controlled to maintain the current gear position;

[0112] When the speed variation is less than the minimum value of the variation range (equivalent to the speed variation being less than the variation range), the transmission of the hybrid vehicle is controlled to switch back to the neutral position after a set time.

[0113] The above embodiments of the present invention Figure 2 The contents of each step are about the specific control logic of "controlling the transmission to maintain the current gear or switch back to the neutral gear when the hybrid vehicle is in a coasting state".

[0114] To further understand this solution, Figure 3 Another flow chart of a control method for a hybrid vehicle is shown, which illustrates the present solution from the perspective of overall control logic; it should be noted that, Figure 3 In the example given, the first vehicle speed threshold is called set vehicle speed 1, the first SOC threshold is called set threshold 1, the second SOC threshold is called set threshold 2, and the range of variation is called set range; Figure 3 The following steps are involved:

[0115] Step S301: determine whether the hybrid vehicle is in a coasting state; if it is in a coasting state, execute step S302; if it is not in a coasting state, end.

[0116] Step S302: Determine whether the vehicle speed is greater than or equal to the set speed 1; if the vehicle speed is greater than or equal to the set speed 1, execute step S303 to maintain the current gear; if the vehicle speed is not greater than or equal to the set speed 1, execute step S304.

[0117] Step S303: Maintain the current gear position and end.

[0118] Step S304: Determine whether the SOC is greater than or equal to a set threshold 1; if the SOC is greater than or equal to the set threshold 1, execute step S305 to switch back to the neutral position after a delay of a set time; if the SOC is not greater than or equal to the set threshold 1, execute step S306.

[0119] Step S305: switch back to the neutral position after a set delay time, and end.

[0120] Step S306: Determine whether the SOC is less than or equal to the set threshold 2; if the SOC is less than or equal to the set threshold 2, execute step S303 to maintain the current gear; if the SOC is not less than or equal to the set threshold 2, execute step S307.

[0121] Step S307: Determine whether the hybrid vehicle is running on an uphill or flat road; if the hybrid vehicle is running on an uphill or flat road, execute step S305 to switch back to the neutral position after a set delay time; if the hybrid vehicle is running on a downhill road, execute step S308.

[0122] Step S308: Calculate the speed variation within a set time.

[0123] Step S309: If the speed change is less than the set range, switch back to neutral after the set time has elapsed, and the process ends.

[0124] Step S310: If the vehicle speed variation is within or greater than the set range, maintain the current gear and end.

[0125] It should be noted that Figure 3 The execution principle of each step in the above-mentioned embodiment of the present invention can be found in Figure 1 and Figure 2 The relevant contents in will not be repeated here.

[0126] It can be seen from the contents of the above embodiments that this solution fully considers factors such as the energy consumption of the hybrid vehicle, the road conditions, and driving safety of the hybrid vehicle. It optimizes the control of the vehicle speed, gear and SOC during the high-speed gliding of the hybrid vehicle, minimizes the kinetic energy loss of the hybrid vehicle during gliding, and takes into account the power demand of the electronic accessories of the hybrid vehicle, which is beneficial to reducing the fuel consumption of the hybrid vehicle throughout the driving cycle.

[0127] Corresponding to the control method of a hybrid vehicle provided by the above embodiment of the present invention, see Figure 4 , the embodiment of the present invention also provides a structural block diagram of a control system of a hybrid vehicle, the control system includes: an acquisition unit 100, a judgment unit 200 and a control unit 300;

[0128] The acquisition unit 100 is used to acquire vehicle operation data of the hybrid vehicle when the hybrid vehicle is running. The vehicle operation data at least includes vehicle speed, slope, SOC and throttle opening.

[0129] The judgment unit 200 is used to judge whether the hybrid vehicle is in a coasting state based on the vehicle operation data.

[0130] The control unit 300 is used to control the hybrid vehicle to maintain the current gear or switch back to the neutral gear according to the vehicle speed, SOC and slope when the hybrid vehicle is in a coasting state.

[0131] In an embodiment of the present invention, when it is determined that the hybrid vehicle is in a coasting state, the hybrid vehicle is controlled to maintain the current gear or switch back to the neutral gear according to the vehicle speed, SOC and slope, thereby reducing fuel consumption in the entire driving cycle and meeting the power demand of the entire vehicle, avoiding the engine's reverse drag time for too long, reducing the energy consumption of the entire vehicle and improving the thermal management effect of the engine.

[0132] Preferably, combined Figure 4 The control unit 300 includes a first judgment module, a first control module, a second judgment module, a second control module, a third judgment module, a third control module and a fourth control module. The execution principle of each module is as follows:

[0133] The first judgment module is used to judge whether the vehicle speed is greater than or equal to a first vehicle speed threshold.

[0134] The first control module is used to control the hybrid vehicle to maintain a current gear if the vehicle speed is greater than or equal to a first vehicle speed threshold.

[0135] The second judgment module is used to judge whether the SOC is within a preset SOC range if the vehicle speed is less than a first vehicle speed threshold, the preset SOC range being composed of a first SOC threshold and a second SOC threshold, and the first SOC threshold being greater than the second SOC threshold.

[0136] The second control module is used to control the hybrid vehicle to maintain the current gear position if the SOC is not within the preset SOC range, or to control the hybrid vehicle to switch back to the neutral gear position after a delay of a set time.

[0137] In a specific implementation, the second control module is specifically used to: when the SOC is greater than or equal to the first SOC threshold, control the hybrid vehicle to switch back to the neutral gear after a set delay time; when the SOC is less than or equal to the second SOC threshold, control the hybrid vehicle to maintain the current gear.

[0138] The third judgment module is used to judge whether the road condition on which the hybrid vehicle is running is a downhill road condition based on the slope if the SOC is within a preset SOC range.

[0139] The third control module is used to control the hybrid vehicle to switch back to the neutral position after a delay of a set time if the road condition on which the hybrid vehicle is running is not a downhill road condition.

[0140] The fourth control module is used to control the hybrid vehicle to maintain the current gear or switch back to the neutral gear based on the set time and vehicle speed if the road condition on which the hybrid vehicle is running is a downhill road condition.

[0141] In a specific implementation, the fourth control module is specifically used to: if the road condition on which the hybrid electric vehicle is running is a downhill road condition, calculate the speed change amplitude of the vehicle speed within a set time; when the speed change amplitude is within a preset change amplitude range, or when the speed change amplitude is greater than the maximum value of the change amplitude range, control the hybrid electric vehicle to maintain the current gear;

[0142] When the speed variation is less than the minimum value of the variation range, the hybrid vehicle is controlled to switch back to the neutral position after a set time.

[0143] Preferably, combined Figure 4 The content shown, the judgment unit 200 includes an acquisition module and a determination module, and the execution principle of each module is as follows:

[0144] The acquisition module is used to acquire, based on the vehicle operation data, a first duration during which the vehicle speed is continuously higher than a second vehicle speed threshold, and a second duration during which the throttle opening is continuously 0.

[0145] The determination module is used to determine that the hybrid vehicle is in a coasting state when the first duration and the second duration are both greater than a duration threshold.

[0146] In summary, the embodiments of the present invention provide a control method and system for a hybrid vehicle. When it is determined that the hybrid vehicle is in a coasting state, the hybrid vehicle is controlled to maintain the current gear or switch back to the neutral gear according to the vehicle speed, SOC and slope, thereby reducing fuel consumption in the entire driving cycle and meeting the power demand of the entire vehicle, avoiding the engine's reverse drag time for too long, reducing the energy consumption of the entire vehicle and improving the thermal management effect of the engine.

[0147] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without creative work.

[0148] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0149] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a hybrid vehicle, characterized in that: The method comprises: When the hybrid vehicle is running, obtaining vehicle operation data of the hybrid vehicle, the vehicle operation data at least including vehicle speed, slope, battery state of charge SOC and throttle opening; Based on the vehicle operation data, determining whether the hybrid vehicle is in a coasting state; When the hybrid electric vehicle is in a coasting state, controlling the hybrid electric vehicle to maintain a current gear or switch back to a neutral gear according to the vehicle speed, the SOC and the slope; Wherein, controlling the hybrid electric vehicle to maintain the current gear or switch back to the neutral gear according to the vehicle speed, the SOC and the slope includes: determining whether the vehicle speed is greater than or equal to a first vehicle speed threshold; If the vehicle speed is greater than or equal to a first vehicle speed threshold, controlling the hybrid vehicle to maintain a current gear position; If the vehicle speed is less than the first vehicle speed threshold, determining whether the SOC is within a preset SOC range, the preset SOC range being composed of a first SOC threshold and a second SOC threshold, the first SOC threshold being greater than the second SOC threshold; If the SOC is not within the preset SOC range, controlling the hybrid electric vehicle to maintain the current gear position, or controlling the hybrid electric vehicle to switch back to the neutral gear position after a delay of a set time; If the SOC is within the preset SOC range, determining whether the road condition on which the hybrid electric vehicle is running is a downhill road condition based on the slope; If the road condition on which the hybrid electric vehicle is running is not a downhill road condition, controlling the hybrid electric vehicle to switch back to the neutral position after a delay of a set time; If the road condition on which the hybrid electric vehicle is running is a downhill road condition, based on the set time and the vehicle speed, the hybrid electric vehicle is controlled to maintain the current gear position or switch back to the neutral gear position.

2. The method according to claim 1, characterized in that If the SOC is not within the preset SOC range, controlling the hybrid electric vehicle to maintain the current gear position, or controlling the hybrid electric vehicle to switch back to the neutral gear position after a delay of a set time, including: When the SOC is greater than or equal to the first SOC threshold, controlling the hybrid electric vehicle to switch back to the neutral position after a delay of a set time; When the SOC is less than or equal to the second SOC threshold, the hybrid vehicle is controlled to maintain the current gear.

3. The method according to claim 1, characterized in that If the road condition on which the hybrid electric vehicle is running is a downhill road condition, based on the set time and the vehicle speed, controlling the hybrid electric vehicle to maintain the current gear position or switch back to the neutral gear position includes: If the road condition on which the hybrid electric vehicle is running is a downhill road condition, calculating the speed change amplitude of the vehicle within the set time; When the vehicle speed variation range is within a preset variation range, or when the vehicle speed variation range is greater than a maximum value of the variation range, controlling the hybrid vehicle to maintain a current gear position; When the vehicle speed variation is less than the minimum value of the variation range, the hybrid vehicle is controlled to switch back to the neutral position after the set time has elapsed.

4. The method according to any one of claims 1 to 3, characterized in that: Determining whether the hybrid electric vehicle is in a coasting state based on the vehicle operation data includes: Based on the vehicle operation data, obtaining a first duration during which the vehicle speed is continuously higher than a second vehicle speed threshold, and obtaining a second duration during which the throttle opening is continuously 0; When the first duration and the second duration are both greater than a duration threshold, it is determined that the hybrid vehicle is in a coasting state.

5. A control system for a hybrid vehicle, characterized in that: The system comprises: An acquisition unit, used for acquiring vehicle operation data of the hybrid vehicle when the hybrid vehicle is running, wherein the vehicle operation data at least includes vehicle speed, slope, battery state of charge SOC and throttle opening; a judgment unit, configured to judge whether the hybrid electric vehicle is in a coasting state based on the vehicle operation data; a control unit, configured to control the hybrid vehicle to maintain a current gear or switch back to a neutral gear according to the vehicle speed, the SOC and the slope when the hybrid vehicle is in a coasting state; Wherein, the control unit comprises: A first judging module, used to judge whether the vehicle speed is greater than or equal to a first vehicle speed threshold; A first control module, configured to control the hybrid electric vehicle to maintain a current gear if the vehicle speed is greater than or equal to a first vehicle speed threshold; A second judgment module is used to judge whether the SOC is within a preset SOC range if the vehicle speed is less than the first vehicle speed threshold, the preset SOC range being composed of a first SOC threshold and a second SOC threshold, and the first SOC threshold is greater than the second SOC threshold; A second control module is used to control the hybrid electric vehicle to maintain the current gear position if the SOC is not within the preset SOC range, or to control the hybrid electric vehicle to switch back to the neutral gear position after a delay of a set time; A third judgment module is used to judge whether the road condition on which the hybrid electric vehicle is running is a downhill road condition based on the slope if the SOC is within the preset SOC range; A third control module, configured to control the hybrid vehicle to switch back to a neutral position after a delay of a set time if the road condition on which the hybrid vehicle is running is not a downhill road condition; The fourth control module is used to control the hybrid vehicle to maintain the current gear or switch back to the neutral gear based on the set time and the vehicle speed if the road condition on which the hybrid vehicle is running is a downhill road condition.

6. The system according to claim 5, characterized in that The second control module is specifically used to: when the SOC is greater than or equal to the first SOC threshold, control the hybrid electric vehicle to switch back to the neutral gear after a set delay time; when the SOC is less than or equal to the second SOC threshold, control the hybrid electric vehicle to maintain the current gear.

7. The system according to claim 5, characterized in that The fourth control module is specifically used to: if the road condition on which the hybrid electric vehicle is running is a downhill road condition, calculate the speed change amplitude of the vehicle within the set time; When the vehicle speed variation range is within a preset variation range, or when the vehicle speed variation range is greater than a maximum value of the variation range, controlling the hybrid vehicle to maintain a current gear position; When the vehicle speed variation is less than the minimum value of the variation range, the hybrid vehicle is controlled to switch back to the neutral position after the set time has elapsed.

8. The system according to any one of claims 5 to 7, characterized in that: The judging unit comprises: an acquisition module, configured to acquire, based on the vehicle operation data, a first duration during which the vehicle speed is continuously higher than a second vehicle speed threshold, and a second duration during which the throttle opening is continuously 0; The determination module is configured to determine that the hybrid electric vehicle is in a coasting state when both the first duration and the second duration are greater than a duration threshold.

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