Control method and device of hybrid vehicle, controller and vehicle

Abstract

The invention provides a hybrid vehicle control method and device, a controller and a vehicle, and is applied to the technical field of vehicle control. The method comprises the steps that when the electric quantity of a power battery is low and the state of an engine is abnormal, the speed interval where the current speed is located is determined, the speed interval is a first interval larger than a first speed threshold value, a second interval smaller than a second speed threshold value or a third interval between the first speed threshold value and the second speed threshold value, and the first speed threshold value is larger than the second speed threshold value; if the current moment is in the third interval, determining a historical speed within a preset duration before the current moment; if the change of the historical speed along with the time is a speed reduction trend, determining a target energy recovery torque corresponding to the current speed, and increasing the energy recovery torque along with the reduction of the speed; and executing the target energy recovery moment. By means of the method, electricity recovery is gradually increased, more electricity is recovered for the user to move the car for self-rescue in emergency, and the response time of the user under the low electricity is prolonged.

Description

Technical Field

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

[0002] In hybrid vehicles, the power battery replaces part of the engine's power source. Typically, when the power battery reaches a certain level of power, the engine will start to maintain the vehicle's power output and prevent the power battery from overcharging or over-discharging during use.

[0003] When the power battery continues to drop to a certain threshold, but the engine cannot be started due to its own problems or other reasons, the vehicle control unit will control the vehicle to directly exit the high-voltage state. The vehicle will break down, making it unable to move and may even stop in the middle of the road, affecting driving safety.

[0004] Therefore, how to allow users to have more time to react before the vehicle exits the high-pressure state is an urgent problem to be solved. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a control method for a hybrid vehicle to solve the safety hazard problem of the vehicle being stranded due to a short user reaction time when the power battery of the hybrid vehicle is low and the engine is not started; a second purpose is to provide a control device for a hybrid vehicle; a third purpose is to provide a controller; and a fourth purpose is to provide a vehicle.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present application provides a control method for a hybrid vehicle, the method comprising:

[0008] When the power battery level is lower than the power threshold and the engine status is abnormal, obtain the current speed of the vehicle;

[0009] determining a speed interval in which the current speed is located, the speed interval being a first interval greater than a first speed threshold, a second interval less than a second speed threshold, or a third interval between the first speed threshold and the second speed threshold, wherein the first speed threshold is greater than the second speed threshold;

[0010] If the current speed is within the third interval, determining the historical speed within a preset time period before the current moment;

[0011] If the historical speed shows a downward trend over time, then according to the preset mapping relationship between speed and energy recovery torque, determine the target energy recovery torque corresponding to the current speed, where the energy recovery torque and speed have a negative correlation in the mapping relationship;

[0012] Execute the target energy recovery torque for kinetic energy recovery.

[0013] Through the above technical means, when the power battery has low power and the engine is not started, and the speed is within the third range, the energy recovery torque is gradually increased as the speed decreases. On the one hand, it can improve the power recovery and provide more power for the user's emergency self - rescue; on the other hand, as the speed decreases, the energy recovery torque gradually increases, avoiding the user feeling abrupt due to suddenly adopting the maximum energy recovery torque.

[0014] Furthermore, the method further includes:

[0015] If the historical speed shows an upward trend or a stable trend over time, then execute the preset maximum energy recovery torque for kinetic energy recovery.

[0016] According to the above means, within the third range, when the speed increases, the maximum energy recovery torque is executed when the user is not accelerating, so as to recover as much power as possible.

[0017] Furthermore, the method further includes:

[0018] Cancel the torque output of the power battery.

[0019] Furthermore, the method further includes:

[0020] If the current speed is within the first range, obtain the brake pedal state;

[0021] If the brake pedal state is non - braking, then prohibit energy recovery;

[0022] If the brake pedal state is braking, then execute the preset conventional energy recovery torque for kinetic energy recovery.

[0023] According to the above technical means, when the speed is relatively high, to extend the vehicle driving range, energy recovery is prohibited in the non - braking state.

[0024] Furthermore, the method further includes:

[0025] If the current speed is within the second range, then execute the preset maximum energy recovery torque for kinetic energy recovery, and cancel the torque output of the power battery.

[0026] According to the above technical means, when the speed decreases to the second range and the speed is relatively low, it recovers with the maximum energy recovery torque to recover as much power as possible.

[0027] Further, the method further includes:

[0028] When the current speed is less than a preset third speed threshold, prompt the user whether to select a self-rescue movement mode, where the third speed threshold is less than the second speed threshold;

[0029] If the user selects the self-rescue movement mode, maintain the high-voltage state of the vehicle within a preset time period and limit the vehicle speed;

[0030] If the user does not select the self-rescue movement mode, exit the high-voltage state.

[0031] Further, the method further includes:

[0032] Obtain the temperature and total driving mileage of the power battery;

[0033] Determine the power threshold according to the temperature and the total driving mileage.

[0034] According to the above technical means, correct the power threshold according to the temperature and total driving mileage, and improve the accuracy of the vehicle's judgment of the low-power state.

[0035] In a second aspect, the present application provides a control device for a hybrid vehicle, and the device includes:

[0036] An acquisition module, configured to obtain the current speed of the vehicle when the power of the power battery is lower than the power threshold and the engine state is abnormal;

[0037] A first determination module, configured to determine the speed range in which the current speed is located, where the speed range is a first range greater than a first speed threshold, a second range less than a second speed threshold, or a third range between the first speed threshold and the second speed threshold, where the first speed threshold is greater than the second speed threshold;

[0038] A second determination module, configured to determine the historical speed within a preset time period before the current moment if the current speed is in the third range;

[0039] A third determination module, configured to determine the target energy recovery torque corresponding to the current speed according to a preset mapping relationship between speed and energy recovery torque if the historical speed shows a decreasing trend over time, and the energy recovery torque and speed in the mapping relationship are negatively correlated;

[0040] An execution module, configured to execute the target energy recovery torque for kinetic energy recovery.

[0041] In a third aspect, the present application provides a controller, including: a memory, a processor;

[0042] The memory stores computer-executable instructions;

[0043] The processor executes the computer-executable instructions stored in the memory, such that the processor executes the method according to any one of the first aspect.

[0044] In a fourth aspect, the present application provides a vehicle, which includes a vehicle body, and a speed sensor, an engine, a power battery, and a controller disposed on the vehicle body, where the controller is configured to execute the method according to any one of the first aspect.

[0045] The present application provides a control method, device, controller, and vehicle for a hybrid vehicle. The method includes: when the power of the power battery is lower than a power threshold and the engine state is abnormal, obtaining the current speed of the vehicle; determining the speed interval in which the current speed is located, where the speed interval is a first interval greater than a first speed threshold, a second interval less than a second speed threshold, or a third interval between the first speed threshold and the second speed threshold, where the first speed threshold is greater than the second speed threshold; if the current speed is in the third interval, determining the historical speed within a preset time period before the current moment; if the historical speed shows a decreasing trend over time, determining a target energy recovery torque corresponding to the current speed according to a preset mapping relationship between speed and energy recovery torque, where the energy recovery torque and speed are negatively correlated in the mapping relationship; and executing the target energy recovery torque for kinetic energy recovery. Through the above method, when the hybrid vehicle has low power, an abnormal engine state, and the speed drops to the second interval, the energy recovery torque is slowly increased. On the one hand, more power is recovered, providing more power for subsequent emergency vehicle relocation and self-rescue use, and improving the reaction time of the user in the low-power situation. On the other hand, the energy recovery torque is dynamically increased according to the vehicle speed, avoiding a sudden forced deceleration when the vehicle speed drops to the second interval, improving the driving smoothness, and also avoiding user discomfort or panic caused by severe deceleration, thus enhancing the user experience. Description of the Drawings

[0046] The drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0047] Figure 1 Flow schematic of a control method for a hybrid vehicle provided by the present application Figure 1 ;

[0048] Figure 2 Flow schematic of a control method for a hybrid vehicle provided by the present application Figure 2 ;

[0049] Figure 3Flow schematic of a control method for a hybrid vehicle provided by this application Figure 3 ;

[0050] Figure 4 Flow schematic of a control method for a hybrid vehicle provided by this application Figure 4 ;

[0051] Figure 5 Structural schematic diagram of a control device for a hybrid vehicle provided by this application;

[0052] Figure 6 Structural schematic diagram of a controller provided by this application.

[0053] Through the above-mentioned drawings, specific embodiments of this application have been shown, and there will be more detailed descriptions hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of this application in any way, but to illustrate the concept of this application to those skilled in the art by referring to specific embodiments. Specific Embodiments

[0054] The following will describe the embodiments of the present invention with reference to the drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, rather than for limiting the protection scope of the present invention.

[0055] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0056] For a hybrid electric vehicle, when the battery power is used up to a certain threshold, the vehicle control unit will start the engine to maintain the power output of the vehicle. However, when the battery power of the vehicle continues to drop to a certain threshold and the engine cannot start normally due to other or its own reasons, the vehicle control unit (VCU) controls the vehicle to exit the high-voltage state, resulting in the user being unable to timely control the vehicle to the roadside and causing the vehicle to break down in the middle of the road.

[0057] In view of the above problems, the present application provides a control method for a hybrid vehicle. When the power battery power continuously drops to a certain threshold and the engine cannot be started, different control strategies are executed according to the vehicle speed. When the vehicle speed is relatively high, vehicle driving is prioritized to enable the vehicle to travel a longer distance. When the vehicle speed drops to a certain speed threshold, the energy recovery ability of the vehicle is gradually increased to recover more power, increase the user's reaction time in case of breakdown, and gradually transitioning the energy recovery torque can improve the user's driving experience. In some scenarios, after the vehicle speed drops to a certain speed threshold, if the vehicle speed gradually increases again due to reasons such as going downhill and becomes greater than the speed threshold, energy recovery is performed with the maximum energy recovery torque to recover more power.

[0058] The following uses specific embodiments to detail the technical solution of the present application and how the technical solution of the present application solves the above technical problems. These several specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0059] Figure 1 Flow schematic of a control method for a hybrid vehicle provided by the present application Figure 1 , as Figure 1 shown, includes the following steps:

[0060] S101. When the power of the power battery is lower than the power threshold and the engine state is abnormal, obtain the current speed of the vehicle.

[0061] In this step, the set power threshold can be less than the motor startup power of the hybrid vehicle. During vehicle driving, the power of the power battery of the hybrid vehicle is obtained in real time. When the power of the power battery is less than the motor startup power, at this time, the vehicle control unit should start the engine to provide power, but due to the insufficient existing battery power to start the engine or the engine cannot be started, the power of the power battery continuously drops. When the power of the power battery is lower than the preset power threshold, obtain the engine state. When the engine is in an abnormal state (for example, unable to start state, or engine failure state), obtain the current speed of the vehicle.

[0062] S102. Determine the speed range where the current speed is located. The speed range is the first range greater than the first speed threshold, the second range less than the second speed threshold, or the third range between the first speed threshold and the second speed threshold, where the first speed threshold is greater than the second speed threshold.

[0063] The power of the power battery being lower than the power threshold indicates that the vehicle enters a low-power state. To provide the user with as long a reaction time as possible, different control strategies need to be determined according to the current speed of the vehicle.

[0064] Pre-divide at least three speed intervals: a first interval greater than the first speed threshold, a second interval less than the second speed threshold, and a third interval between the first speed threshold and the second speed threshold. Determine the interval in which the current speed is located and execute the control strategy for that interval. Among them, the first speed threshold can be set to 40 km / h, 50 km / h, or 60 km / h. The second speed threshold can be set to 20 km / h, 25 km / h, or 30 km / h. Exemplarily, the first speed threshold is 40 km / h and the second speed threshold is 20 km / h. The first interval is greater than 40 km / h, the second interval is 0 - 20 km / h, and the third interval is 20 km / h - 40 km / h.

[0065] If the current speed is in the first interval, the vehicle speed is relatively fast, and the vehicle is not restricted so that the user can drive a longer distance.

[0066] If the current speed is in the second interval, the vehicle speed is relatively slow. Prompt the user to take measures for vehicle self-rescue, pull over to the side of the road, and perform kinetic energy recovery with the maximum energy recovery torque.

[0067] To prevent the sudden change caused by the vehicle directly adopting the maximum energy recovery torque, when the current speed drops to the third interval and continues to drop, a gradually changing energy recovery torque can be adopted. While increasing the kinetic energy recovery, it can avoid the sudden change caused by directly adopting the maximum energy recovery torque when the speed reaches the second interval, improve the user's driving experience, and avoid the user suddenly feeling panicked due to deceleration.

[0068] S103. If the current speed is in the third interval, determine the historical speed within a preset duration before the current moment.

[0069] In this step, when the current speed is in the third interval, it is necessary to judge the trend of speed change, and different control strategies are adopted for different change trends. To judge the trend of speed change, the historical speed within a period of time is required. Therefore, obtain the historical speed within the preset duration before the current moment to calculate the speed change trend. Among them, the preset duration is the duration from the previous moment to the current moment, and this preset duration can be 5 seconds, 10 seconds, or 30 seconds, without specific limitation.

[0070] S104. If the historical speed shows a downward trend over time, determine the target energy recovery torque corresponding to the current speed according to the preset mapping relationship between speed and energy recovery torque, and the energy recovery torque and speed in the mapping relationship are negatively correlated.

[0071] After obtaining the historical speed, judge the change trend of the historical speed.

[0072] In one implementation, the overall speed difference is obtained by subtracting the speed with the earliest time in the historical speeds from the current speed. If the overall speed difference is less than the preset speed difference, it indicates a downward trend. The preset speed difference can be -1 km / h, -2 km / h, or -5 km / h.

[0073] In one implementation, the speed difference between each adjacent time point is calculated by subtracting the speed of the previous moment from the speed of the next moment, that is, the change in speed within each adjacent time interval. If the speed difference is less than 0, it means that the speed has decreased within this time interval. It is determined whether there is a continuous downward trend in the historical speed by judging whether multiple speed differences are negative. If the number of speed differences less than 0 exceeds the preset percentage (for example, 70%), it indicates a downward trend.

[0074] When it is determined that the vehicle speed is in a downward trend, it means that the vehicle is decelerating under low battery conditions, and the current speed is less than the first speed threshold and continues to decrease. In this case, the lower the current speed of the vehicle, the greater the energy recovery intensity. A mapping relationship between speed and energy recovery torque is preset, and in this mapping relationship, the smaller the speed, the greater the energy recovery torque. The target energy recovery torque corresponding to the current speed is determined from the mapping relationship.

[0075] S105. Execute the target energy recovery torque for kinetic energy recovery.

[0076] The controller adjusts the braking system according to the target energy recovery torque, so that the motor can convert kinetic energy into electrical energy and feedback it to the power battery during braking.

[0077] Optionally, during the execution of kinetic energy recovery, the user is reminded that the battery is about to run out and to pull over and stop.

[0078] This embodiment provides a control method for a hybrid vehicle, the method comprising: when the power battery charge is lower than a charge threshold and the engine state is abnormal, obtaining the current speed of the vehicle; determining the speed range in which the current speed is located, wherein the speed range is a first range greater than a first speed threshold, a second range less than a second speed threshold, or a third range between the first speed threshold and the second speed threshold, wherein the first speed threshold is greater than the second speed threshold; if the current speed is in the third range, determining the historical speed within a preset time period before the current moment; if the historical speed changes over time in a decreasing trend, determining a target energy recovery torque corresponding to the current speed based on a preset mapping relationship between speed and energy recovery torque, wherein the energy recovery torque and speed are negatively correlated in the mapping relationship; and executing the target energy recovery torque to recover kinetic energy. Through the above method, when the hybrid vehicle is low in power, the engine state is abnormal, and the speed drops to the second range, the energy recovery torque is slowly increased, thereby increasing power recovery and providing more electrical energy for subsequent emergency vehicle maneuvering and self-rescue. On the other hand, the energy recovery torque is increased dynamically according to the vehicle speed, avoiding sudden forced deceleration when reaching the second interval, improving driving smoothness, and avoiding user discomfort or panic caused by severe deceleration, thereby improving the user experience.

[0079] The following describes a control method when the vehicle speed is in the first range with an embodiment.

[0080] Figure 2 A schematic diagram of a control method for a hybrid vehicle provided in this application Figure 2 ,like Figure 2 As shown, the following steps are included:

[0081] S201. When the power level of the power battery is lower than a power threshold and the engine state is abnormal, obtain the current speed of the vehicle.

[0082] S202: Determine a speed interval in which the current speed is located, where the speed interval is a first interval greater than a first speed threshold, a second interval less than a second speed threshold, or a third interval between the first speed threshold and the second speed threshold, wherein the first speed threshold is greater than the second speed threshold.

[0083] The above steps S201 and S202 are the same as the above steps S101 and S102, and are not described again here.

[0084] S203: If the current speed is in the first interval, obtain the brake pedal state.

[0085] S204: If the brake pedal is in the non-braking state, energy recovery is prohibited.

[0086] If the current speed is in the first interval, it means that the vehicle speed is relatively fast. When the user does not step on the brake pedal, the vehicle's energy recovery should be limited to ensure that the vehicle can maintain a longer driving distance without interfering with normal driving.

[0087] S205: If the brake pedal is in the braking state, the preset conventional energy recovery torque is executed to recover kinetic energy.

[0088] If the driver depresses the brake pedal, the vehicle is braking. At this point, the controller applies the preset normal regenerative torque to regenerate kinetic energy. This normal regenerative torque is dependent on the braking demand and is adjusted to suit the current braking intensity, ensuring safe braking and maximum energy recovery.

[0089] This implementation provides a control method for low battery, engine anomalies, or speeds above a first speed threshold. During non-braking conditions, energy regeneration is disabled to ensure the vehicle can maintain a long driving range without interfering with normal driving. During braking, energy regeneration is performed based on braking demand to maximize energy recovery.

[0090] The following describes a control method when the vehicle speed is in the second range with an embodiment.

[0091] Figure 3 A schematic diagram of a control method for a hybrid vehicle provided in this application Figure 3 ,like Figure 3 As shown, the following steps are included:

[0092] S301. When the power level of the power battery is lower than a power threshold and the engine state is abnormal, obtain the current speed of the vehicle.

[0093] S302: Determine a speed interval in which the current speed is located, where the speed interval is a first interval greater than a first speed threshold, a second interval less than a second speed threshold, or a third interval between the first speed threshold and the second speed threshold, wherein the first speed threshold is greater than the second speed threshold.

[0094] The above steps S301 and S302 are the same as the above steps S101 and S102, and are not described again here.

[0095] S303: If the current speed is in the second interval, the preset highest energy recovery torque is executed to recover kinetic energy, and the torque output of the power battery is canceled.

[0096] When the current speed is less than the second speed threshold, cancel the torque output of the power battery, that is, no power can be provided even if the driver accelerates, and the vehicle is only driven by the existing coasting ability of the vehicle, and kinetic energy recovery is performed with a preset maximum energy recovery torque.

[0097] Optionally, turn on the turtle light in the vehicle and give a prompt to remind the driver to pull over and stop.

[0098] Through the above embodiments, when the power battery is abnormal at low power and the speed is less than the second speed threshold, the maximum energy recovery torque is adopted for kinetic energy recovery to increase the power battery power, no longer respond to the user's acceleration request, and prompt the user to pull over and stop.

[0099] In some special scenarios, after the vehicle speed drops to the second interval, the torque output of the power battery is restricted and the acceleration pedal cannot be used for acceleration because on a downhill section, the speed does not continue to decrease but increases. The control method in this scenario will be introduced below.

[0100] First, determine the speed change trend according to the historical speed. In one implementation, subtract the speed with the earliest time in the historical speed from the current speed to obtain the overall speed difference. If the overall speed difference is greater than the preset rising speed difference, it is determined that the speed is in an upward trend. The preset rising speed difference can be 1 km / h, 2 km / h, or 5 km / h. If the overall speed difference is less than the preset falling speed difference (such as -1 km / h, -2 km / h, or -5 km / h), it indicates that the speed is in a downward trend. If the overall speed difference is greater than the falling speed difference and less than the rising speed difference, it is determined that the speed is in a stable trend.

[0101] In one implementation, subtract the speed of the previous moment from the speed of the next moment to calculate the speed difference between each adjacent time point, that is, the change in speed within each adjacent time interval. If the speed difference is greater than 0, it means that the speed has increased within this time interval. Determine whether the historical speed has a continuous upward trend by judging whether multiple speed differences are positive. If the number of speed differences greater than 0 exceeds the preset percentage (such as 70%), it indicates that the speed is in an upward trend. If the number of speed differences less than 0 is lower than the preset percentage, it is determined that the speed is in a downward trend, and if it is between the two, it is determined that the speed is in a stable trend.

[0102] After determining that the vehicle is in an upward speed trend or a stable speed trend in the third interval, two control methods can be selected for torque control.

[0103] The first method: According to the mapping relationship between speed and energy recovery torque, determine the recovery torque at the current speed, that is, as the current speed increases, the energy recovery torque becomes smaller and smaller. When the speed is in the first interval, energy recovery is disabled. This method is to ensure that the vehicle can travel a longer distance. After the downhill road ends, the vehicle will decelerate, and the vehicle speed may return to the third interval after deceleration. The execution logic after deceleration is similar to steps S101 - S105.

[0104] In the second method, the user does not step on the accelerator pedal, but the historical speed shows an upward trend or a stable trend over time. To increase the ability of power recovery, the preset maximum energy recovery torque is executed for kinetic energy recovery. Optionally, when the speed is on an upward trend, the torque output of the power battery is cancelled to save the power of the power battery, and the vehicle travels only relying on the inertia of going downhill.

[0105] In this scenario, if the current speed of the vehicle continues to accelerate and reaches the first interval, kinetic energy recovery is still performed with the maximum energy recovery torque. After the downhill road ends, the vehicle will decelerate. After the vehicle speed is in the third interval after deceleration, kinetic energy recovery is still performed with the maximum energy recovery torque. That is, as long as the speed has reached the second interval and kinetic energy recovery is performed with the maximum energy recovery torque, as long as the power of the power battery is less than the power threshold, kinetic energy recovery is performed with the maximum energy recovery torque.

[0106] In some scenarios, after the vehicle speed drops to the third interval, the user steps on the accelerator pedal to accelerate. At this time, the current vehicle speed shows an upward trend or a stable trend within the third interval. Due to the speed increase caused by the user's demand, kinetic energy recovery can be cancelled to meet the user's demand.

[0107] In some embodiments, when the vehicle speed drops to the second interval and is lower than the third speed threshold in the second interval, the vehicle-mounted system prompts the user whether to adopt the autonomous self-rescue movement mode. If the user does not select the autonomous self-rescue movement mode, the vehicle exits the high-voltage state and cannot move; if the user selects the autonomous self-rescue movement mode through the vehicle-mounted system, the vehicle maintains the high-voltage state for a short time and enters a restricted drivable state, enabling the user to move the vehicle short distances without vehicle speed or at extremely low speeds without the need for professional maintenance or the support of professional maintenance personnel.

[0108] The following introduces the method of emergency self-rescue control when the power is low with specific examples.

[0109] Figure 4 The flowchart of a control method for a hybrid vehicle provided by this application Figure 4 , as Figure 4 shown, includes the following steps:

[0110] Step S401: Determine whether the vehicle activates the emergency self - rescue control mode.

[0111] The vehicle control unit (VCU) determines whether to activate this function by judging information such as the high - voltage state of the vehicle's power battery, the SOC level of the power battery, whether the engine is running, and the working mode of the motor in the vehicle's power system operation state, and prompts the user through the instrument or the vehicle computer.

[0112] Specifically, the vehicle control unit (VCU) determines the first power threshold according to the working temperature of the power battery cells obtained from the battery management system (BMS for short) and the total pure - electric driving mileage calculated inside the vehicle control unit (VCU). The higher or lower the temperature, the larger the power threshold; the longer the total pure - electric driving mileage, the larger the first power threshold. The power threshold for the low - power state when the battery enters the self - rescue control mode is affected by temperature and driving mileage (or usage duration). Therefore, the first power threshold is corrected by temperature and the total battery driving mileage. After determining the first power threshold, when the vehicle is in the high - voltage activation state, that is, the vehicle's high - voltage power supply system is normal and the power battery SOC is lower than the first power threshold, it is determined whether the engine is not running.

[0113] The state of the engine is abnormal in this scenario. The abnormal state includes that the existing battery power is insufficient to start the engine resulting in the engine not running, or the engine does not work due to its own or external factors, etc.

[0114] The drive motor of the vehicle needs to be in the standby or high - voltage activation state and can rotate under the action of external force.

[0115] When the above information monitored by the vehicle control unit (VCU) is satisfied simultaneously and maintained for a certain period of time, the self - rescue control mode is activated.

[0116] Step S402: Determine whether the vehicle enters the contactless self - rescue control mode.

[0117] The vehicle control unit (VCU) has preset the first speed threshold. By comparing the actual vehicle speed with the first speed threshold, the motion state of the vehicle and the vehicle's motion level are judged. Then different control measures are taken according to the judgment result.

[0118] When the actual vehicle speed is greater than the first speed threshold, it is in the first interval and the vehicle enters the contactless self - rescue control mode.

[0119] When the vehicle speed is lower than the second speed threshold and the vehicle is in the second interval, a prompt is given to ask whether to select to enter the corresponding autonomous self-rescue movement control mode. To prevent changes in the control mode caused by sudden changes in the vehicle speed signal and considering the influence of sensors and the road surface, a third interval with a corresponding hysteresis vehicle speed is set between the first interval and the second interval. Within the third interval, when the speed decreases, the energy recovery torque slowly increases to avoid discomfort caused by sudden changes in the energy recovery torque.

[0120] Step S403: The vehicle enters the non-contact self-rescue control mode, and the vehicle control unit (VCU) controls the vehicle operation according to the vehicle motion state and the driver's operations.

[0121] Specifically, when the vehicle control unit (VCU) monitors valid vehicle speed information, the vehicle speed is higher than the first threshold, the driver does not step on the brake pedal, and the power battery power continuously drops, at this time the vehicle control unit (VCU) prohibits the coasting energy recovery torque, so that the vehicle can travel at a relatively high speed as much as possible; as the vehicle speed decreases, when the vehicle speed is lower than the first speed threshold, the coasting energy recovery torque is gradually increased until the vehicle speed reaches the second speed threshold, and the energy recovery torque is the maximum. During this period, if the driver steps on the brake pedal, the above control is exited following the brake priority principle, and the coasting recovery torque of the preset normal driving condition is adopted, and the braking energy recovery torque is additionally applied.

[0122] When the vehicle control unit (VCU) monitors that the vehicle triggers the non-contact self-rescue mode, the vehicle control unit (VCU) restricts the output of high-voltage power and restricts the energy supply of high-voltage non-driving components such as high-voltage air conditioners to maintain the power supply for the vehicle's drivable state. The lower the SOC, the higher the degree of power supply restriction for high-voltage components.

[0123] Step S404: Judge whether the user selects to enter the autonomous self-rescue movement control mode. If in the autonomous self-rescue movement control mode, the vehicle control unit (VCU) switches to the corresponding control program according to the user's selection result.

[0124] When the power drops continuously to the second threshold, at this time the vehicle head unit or instrument system of the vehicle prompts the user whether to enter the autonomous self-rescue movement mode, and prompts that this mode requires the driver to manually select this mode on the basis of knowing the risk degree, and in order to protect the power battery from over-discharging, this mode can only exist for a short time.

[0125] If the user chooses not to enter, the vehicle control unit (VCU) immediately controls the vehicle to quickly reduce the speed, exits the drivable mode, and then stops the vehicle operation.

[0126] If the user selects to enter, the vehicle control unit (VCU) lowers the power threshold determination threshold for the vehicle to exit the high-voltage state. The vehicle remains in the restricted high-voltage drivable state. At this time, there is no driving energy and energy supply for high-voltage non-driving components in the vehicle, and only basic capabilities such as high-low voltage conversion, basic display, braking, and gear shifting are supported. The vehicle control unit (VCU) limits the maximum output torque of the power battery to the limp-home torque, which needs to be determined in combination with the obtained road gradient. The greater the gradient, the greater the limp-home torque. The turtle lamp is lit, and the driver is prompted to pull over and stop.

[0127] When the user manually selects this mode and when the power battery power drops to this third threshold, the vehicle is controlled to immediately exit the high-voltage state to prevent the situation where the user neglects the battery during vehicle use and causes damage to the power battery.

[0128] In summary, when the hybrid vehicle is in a state of too low power battery power and the engine cannot start or has not started, through the energy output control of the power battery, an emergency self-rescue control method for the vehicle when the power battery power is low is provided for the user. This method includes two levels: contactless autonomous entry and user-selected entry, which minimizes the customer's panic and improves the user's autonomy. It mainly includes that when the vehicle is in a driving state, the power battery power is lower than the power threshold, and the vehicle speed is higher than the first speed threshold, according to the driver's operation, the energy recovery torque is prohibited, and the output of the driving torque and high-voltage non-driving power is restricted; when the vehicle speed continues to drop further below the first threshold, the energy recovery torque intensity is gradually adjusted back, and the speed limit function is executed during this period. When the power battery power continues to drop to the second power threshold, the vehicle-mounted system prompts the vehicle owner whether to use the autonomous self-rescue moving mode. This autonomous self-rescue moving mode includes: prompting the user that the vehicle is speed-limited, the maximum vehicle speed in this mode is lower than the normal crawling vehicle speed, the power output of the power battery is reduced as much as possible, and the remaining battery power is prominently displayed through the vehicle-mounted system or dashboard, and information such as the turtle speed lamp is lit, and the high-voltage state and drivable state of the vehicle are maintained briefly. If the user does not select, the vehicle control unit (VCU) controls the vehicle to stop and immediately drop the high voltage and stop the vehicle operation; if the user selects this self-rescue mode, the vehicle control unit (VCU) controls the vehicle to maintain the basic high-voltage power supply output, basic display, braking, and gear shifting and other most basic moving and safety capabilities. When the battery power further drops to the third power threshold, the vehicle exits the self-rescue mode and then exits the high-voltage state, and the vehicle is in a shutdown state.

[0129] When the vehicle is shut down and the user restarts the vehicle, when the vehicle is in a low-voltage state and the battery power is higher than the third power threshold for entering the self-rescue mode, the user is prompted whether to enable the autonomous self-rescue moving mode, and the user decides whether to enable this mode according to his own judgment.

[0130] Figure 5 The structural schematic diagram of the control device for a hybrid vehicle provided by this application is as follows. Figure 5 As shown, the control device 50 for a hybrid vehicle provided in this embodiment includes:

[0131] An acquisition module 501, configured to obtain the current speed of the vehicle when the power of the power battery is lower than the power threshold and the engine state is abnormal;

[0132] A first determination module 502, configured to determine the speed range in which the current speed is located. The speed range is a first range greater than a first speed threshold, a second range less than a second speed threshold, or a third range between the first speed threshold and the second speed threshold, where the first speed threshold is greater than the second speed threshold;

[0133] A second determination module 503, configured to determine the historical speed within a preset time period before the current moment if the current speed is in the third range;

[0134] A third determination module 504, configured to determine the target energy recovery torque corresponding to the current speed according to a preset mapping relationship between speed and energy recovery torque if the historical speed shows a downward trend over time. In the mapping relationship, the energy recovery torque is negatively correlated with the speed;

[0135] An execution module 505, configured to execute the target energy recovery torque for kinetic energy recovery.

[0136] Optionally, the execution module 505 is further configured to:

[0137] If the historical speed shows an upward trend or a stable trend over time, execute a preset maximum energy recovery torque for kinetic energy recovery.

[0138] Optionally, the execution module 505 is further configured to:

[0139] Cancel the torque output of the power battery.

[0140] Optionally, the acquisition module 501 is further configured to:

[0141] If the current speed is in the first range, obtain the state of the brake pedal;

[0142] Correspondingly, the execution module 505 is further configured to:

[0143] If the brake pedal state is a non-braking state, prohibit energy recovery;

[0144] If the brake pedal state is a braking state, execute a preset conventional energy recovery torque for kinetic energy recovery.

[0145] Optionally, the execution module 505 is further configured to: if the current speed is within the second interval, perform kinetic energy recovery by executing a preset maximum energy recovery torque, and cancel the torque output of the power battery.

[0146] Optionally, the device further includes a prompt module 506, which is configured to:

[0147] When the current speed is less than a preset third speed threshold, prompt the user whether to select a self-rescue movement mode, where the third speed threshold is less than the second speed threshold;

[0148] If the user selects the self-rescue movement mode, maintain the high-voltage state of the vehicle within a preset time period and limit the vehicle speed;

[0149] If the user does not select the self-rescue movement mode, exit the high-voltage state.

[0150] Optionally, the acquisition module 501 is further configured to:

[0151] Acquire the temperature of the power battery and the total driving mileage;

[0152] Determine the power threshold according to the temperature and the total driving mileage.

[0153] The control device for a hybrid vehicle provided in this embodiment can execute the method provided in the above method embodiment, and its implementation principle and technical effects are similar, which will not be elaborated here in this embodiment.

[0154] Figure 6 It is a schematic structural diagram of the controller provided in this application. As Figure 6 shown, the controller 50 provided in this embodiment includes: at least one processor 601 and a memory 602. Optionally, the controller 60 further includes a communication component 603. Among them, the processor 601, the memory 602, and the communication component 603 are connected through a bus 604.

[0155] In a specific implementation process, at least one processor 601 executes the computer execution instructions stored in the memory 602, so that at least one processor 601 executes the above method.

[0156] The specific implementation process of the processor 601 can be referred to the above method embodiment, and its implementation principle and technical effects are similar, which will not be elaborated here in this embodiment.

[0157] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in combination with the invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor.

[0158] The memory may include a random access memory (RAM), and may also include a non-volatile memory (NVM), such as at least one disk memory.

[0159] The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the buses in the drawings of this application are not limited to only one bus or one type of bus.

[0160] This application also provides a computer program product, including a computer program that implements the above method when executed by a processor.

[0161] This application also provides a vehicle, including a vehicle body, an engine, a power battery, and a controller, where the controller is used to implement the method in the above embodiments.

[0162] This application also provides a computer-readable storage medium storing computer-executable instructions that implement the above method when executed by a processor.

[0163] The above-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, a magnetic disk, or an optical disk. The readable storage medium can be any available medium accessible by a general-purpose or special-purpose computer.

[0164] An exemplary readable storage medium is coupled to the processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist as discrete components in a device.

[0165] The division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Additionally, the couplings, direct couplings, or communication connections shown or discussed among each other can be indirect couplings or communication connections through some interfaces, devices, or units, and can be in electrical, mechanical, or other forms.

[0166] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0167] Furthermore, in each embodiment of the present invention, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0168] If a function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or a part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of various embodiments of the present invention. The foregoing storage medium includes: USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs and other various media that can store program codes.

[0169] Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When this program is executed, it executes the steps including the above method embodiments; and the foregoing storage medium includes: ROMs, RAMs, magnetic disks, or optical discs and other various media that can store program codes.

[0170] Finally, it should be noted that: After considering the specification and practicing the invention disclosed herein, those skilled in the art will readily think of other implementation manners of the present invention. The present invention is intended to cover any variations, uses, or adaptive changes of the present invention. These variations, uses, or adaptive changes follow the general principles of the present invention and include common general knowledge or conventional technical means in the technical field not disclosed in the present invention. It is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A control method for a hybrid vehicle, characterized in that The method includes: When the power of the power battery is lower than the power threshold and the engine state is abnormal, obtain the current speed of the vehicle; Determine the speed range where the current speed is located. The speed range is a first range greater than the first speed threshold, a second range less than the second speed threshold, or a third range between the first speed threshold and the second speed threshold, where the first speed threshold is greater than the second speed threshold; If the current speed is in the third range, determine the historical speed within a preset duration before the current moment; If the historical speed shows a downward trend over time, determine the target energy recovery torque corresponding to the current speed according to the preset mapping relationship between speed and energy recovery torque, and the energy recovery torque and speed are negatively correlated in the mapping relationship; Execute the target energy recovery torque for kinetic energy recovery.

2. The method according to claim 1, characterized in that, The method further includes: If the historical speed shows an upward trend or a stable trend over time, execute the preset maximum energy recovery torque for kinetic energy recovery.

3. The method according to claim 2, wherein The method further includes: Cancel the torque output of the power battery.

4. The method according to claim 1, wherein The method further includes: If the current speed is in the first range, obtain the brake pedal state; If the brake pedal state is non-braking, prohibit energy recovery; If the brake pedal state is braking, execute the preset conventional energy recovery torque for kinetic energy recovery.

5. The method according to claim 1, wherein The method further includes: If the current speed is in the second range, execute the preset maximum energy recovery torque for kinetic energy recovery and cancel the torque output of the power battery.

6. The method according to claim 5, wherein The method further includes: When the current speed is less than a preset third speed threshold, prompt the user whether to select a self-rescue movement mode, where the third speed threshold is less than the second speed threshold; If the user selects the self-rescue movement mode, maintain the high-voltage state of the vehicle within a preset time period; If the user does not select the self-rescue movement mode, exit the high-voltage state.

7. The method according to any one of claims 1-6, characterized in that, The method further includes: Obtain the temperature and total driving mileage of the power battery; Determine the power threshold according to the temperature and the total driving mileage.

8. A control device for a hybrid vehicle, characterized in that, The device includes: An acquisition module, configured to obtain the current speed of the vehicle when the power of the power battery is lower than the power threshold and the engine state is abnormal; A first determination module, configured to determine the speed range where the current speed is located. The speed range is a first range greater than the first speed threshold, a second range less than the second speed threshold, or a third range between the first speed threshold and the second speed threshold, where the first speed threshold is greater than the second speed threshold; A second determination module, configured to determine the historical speed within a preset duration before the current moment if the current speed is in the third range; A third determination module, configured to determine the target energy recovery torque corresponding to the current speed according to the preset mapping relationship between speed and energy recovery torque if the historical speed shows a downward trend over time, and the energy recovery torque and speed are negatively correlated in the mapping relationship; An execution module for performing the target energy recovery torque to recover kinetic energy.

9. A controller, characterized in that, It includes: A memory and a processor; The memory stores computer execution instructions; The processor executes the computer execution instructions stored in the memory, so that the processor executes the method according to any one of claims 1-7.

10. A vehicle, characterized in that, The vehicle includes a vehicle body, and a speed sensor, an engine, a power battery and a controller arranged on the vehicle body, and the controller is used to execute the method according to any one of claims 1-7.

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