Vehicle abrupt slope slow descent control method, controller, control system and vehicle

Abstract

The invention discloses a vehicle abrupt slope slow descent control method, a controller, a control system and a vehicle, and the method comprises the steps that when the vehicle is in an abrupt slope slow descent state, the slip rate of the vehicle is obtained; and when the slip rate of the vehicle is larger than a preset slip rate, the vehicle is controlled to enter an anti-lock state, so that the slip rate of the vehicle is reduced to be not larger than the preset slip rate. According to the scheme, when the vehicle is in the abrupt slope slow descent state, the slip rate of the vehicle can be obtained, and when the slip rate of the vehicle is larger than the preset slip rate, the vehicle is controlled to enter the anti-lock state so that the slip rate of the vehicle can be decreased to be not larger than the preset slip rate, and when the vehicle is in the abrupt slope slow descent state, the anti-lock state of the vehicle can be controlled. The slip rate of the vehicle can be controlled within a safe range all the time, stable running of the vehicle is maintained, the vehicle is prevented from falling into a dangerous working condition due to the too large slip rate, and the safety performance is greatly improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle control technology, and in particular to a vehicle steep slope descent control method, a controller, a control system and a vehicle. Background Art

[0002] In the current automobile market, the models mainly equipped with the steep slope descent control function are SUVs and a small number of high-end cars. This function is mainly achieved through the combined effect of engine braking and the car's anti-lock braking system (ABS). It can enable the car driver to pass through a steep downhill section without operating the accelerator and brake pedals, effectively reducing the driver's operating difficulty during the downhill process and improving safety performance.

[0003] In the related art, when a car enters a steep slope and the wheel slip rate is too large, the ABS system sometimes does not intervene to control the slip rate, making the car prone to fall into a dangerous condition. Summary of the invention

[0004] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further described in detail in the Detailed Description of the Invention section. The Summary of the Invention section of this application does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0005] In view of the existing problems, the present application provides a vehicle steep slope descent control method, comprising:

[0006] When the vehicle is in a state of slow descent on a steep slope, obtaining a slip rate of the vehicle;

[0007] When the slip ratio of the vehicle is greater than a preset slip ratio, the vehicle is controlled to enter an anti-lock braking state so that the slip ratio of the vehicle decreases to no greater than the preset slip ratio.

[0008] Exemplarily, before the vehicle is in the steep slope descent state, the method includes:

[0009] When the steep slope descent standby condition is met, the vehicle is controlled to enter the steep slope descent standby state from the steep slope descent off state.

[0010] Exemplarily, the steep slope descent standby conditions include:

[0011] The braking system of the vehicle is free of faults;

[0012] The hill descent control switch is on;

[0013] The vehicle speed is less than the first vehicle speed.

[0014] Exemplarily, the first vehicle speed is 60 km / h.

[0015] Exemplarily, the method further includes:

[0016] When the vehicle is in the steep slope descent standby state, when a steep slope descent intervention condition is met, the vehicle is controlled to enter the steep slope descent state to brake the vehicle.

[0017] Exemplarily, the steep slope descent intervention conditions include:

[0018] The vehicle speed is not less than the second vehicle speed and not greater than the third vehicle speed;

[0019] The slope of the road on which the vehicle is traveling is less than the first slope;

[0020] The accelerator operation signal and the brake pedal operation signal are not received.

[0021] Exemplarily, the third vehicle speed is 38 km / h.

[0022] Exemplarily, the first slope is 6%.

[0023] Exemplarily, controlling the vehicle to enter the steep slope descent state includes:

[0024] Obtaining a steep slope descent speed according to the vehicle speed and the slope of the road on which the vehicle is traveling;

[0025] The vehicle is controlled so that the difference between the vehicle speed and the steep slope descent speed is lower than a preset speed difference.

[0026] Exemplarily, controlling the vehicle so that the difference between the vehicle speed and the steep slope descent speed is lower than a preset speed difference includes:

[0027] Braking the vehicle in a motor feedback braking mode so that the difference between the vehicle speed and the steep slope descent speed is lower than the preset speed difference; or

[0028] The vehicle is braked by a motor feedback and hydraulic hybrid braking mode so that the difference between the vehicle speed and the steep slope descent speed is lower than the preset speed difference.

[0029] Exemplarily, the method further includes:

[0030] When the slip ratio of the vehicle decreases to be no greater than the preset slip ratio, the vehicle is controlled to exit the anti-lock braking state.

[0031] Exemplarily, the method further includes: when the vehicle is in the steep slope descent state, when a steep slope descent state return condition is met, controlling the vehicle to return from the steep slope descent state to the steep slope descent standby state;

[0032] The steep slope descent state return condition includes:

[0033] The vehicle speed is less than the second vehicle speed; or

[0034] The throttle operation signal or the brake pedal operation signal is received.

[0035] Exemplarily, the method further includes:

[0036] When the vehicle is in the steep slope descent control state, when a steep slope descent control state exit condition is met, controlling the vehicle to return from the steep slope descent control state to the steep slope descent control closed state;

[0037] The exit conditions of the steep slope slow descent state include:

[0038] The steep slope descent switch is in the off state.

[0039] Exemplarily, the method further includes:

[0040] When the vehicle is in the steep slope descent standby state, when an exit condition of the steep slope descent standby state is met, controlling the vehicle to exit the steep slope descent standby state;

[0041] The exit conditions of the steep slope descent standby state include:

[0042] The vehicle speed is greater than the first vehicle speed; or

[0043] The steep slope descent switch is in the off state.

[0044] Exemplarily, when the vehicle cannot be controlled to enter the steep slope descent state, the method further includes:

[0045] The vehicle is controlled to enter an electronic parking brake state to brake the vehicle.

[0046] Exemplarily, controlling the vehicle to enter an anti-lock braking state includes:

[0047] The anti-lock state is achieved by controlling the wheel side pressure maintaining and the pressure relief valve to control the wheel side pressure.

[0048] On the other hand, the present application provides a controller, including a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the above-mentioned vehicle steep slope descent control method.

[0049] In another aspect, the present application provides a control system for a vehicle to slowly descend a steep slope, comprising an anti-lock braking system and the above-mentioned controller, wherein:

[0050] The controller is further configured to control the anti-lock braking system to perform anti-lock braking on the vehicle, so that the slip rate of the vehicle is reduced to no more than the preset slip rate.

[0051] Yet another aspect of the present application provides a vehicle, the vehicle comprising the above-mentioned controller, or comprising the above-mentioned control system.

[0052] The vehicle steep slope descent control method, controller, control system and vehicle of the present application can obtain the slip rate of the vehicle when the vehicle is in a steep slope descent state, and when the slip rate of the vehicle is greater than a preset slip rate, control the vehicle to enter an anti-lock braking state to reduce the slip rate of the vehicle to no more than the preset slip rate, so that when the vehicle is in a steep slope descent state, the vehicle slip rate can be always controlled within a safe range, the vehicle's stable driving can be maintained, and the vehicle can be prevented from falling into a dangerous condition due to an excessively large slip rate, thereby greatly improving the safety performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The above and other purposes, features and advantages of the present invention will become more apparent by describing the embodiments of the present invention in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0054] In the attached figure:

[0055] Figure 1 A schematic flow chart of a vehicle steep slope descent control method according to a specific embodiment of the present application is shown.

[0056] Figure 2 A schematic flow chart of a vehicle steep slope descent control method according to another specific embodiment of the present application is shown.

[0057] Figure 3 A schematic structural block diagram of a controller according to a specific embodiment of the present application is shown.

[0058] Figure 4 A schematic structural block diagram of a vehicle steep slope descent control system according to a specific embodiment of the present application is shown. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical scheme and advantages of the present invention more obvious, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention.

[0060] The inventor of the present application discovered that in the related art, the ABS system will intervene and maintain the vehicle speed through braking operation only when the current vehicle speed exceeds the speed upper limit of the hill descent control system. Therefore, under this working logic, when the wheel slip rate is too large, if the current vehicle speed is still within the speed range required by the hill descent control system and the driver does not step on the brake pedal, the ABS system will not intervene to control the slip rate, and an excessively large wheel slip rate will make the car easily fall into a dangerous condition.

[0061] Therefore, in view of the existence of the aforementioned technical problems, the present invention proposes a vehicle steep slope descent control method, a controller, a control system and a vehicle.

[0062] Next, combine Figure 1 To describe a vehicle steep slope descent control method according to a specific embodiment of the present application, Figure 1 FIG. 1 is a schematic flow chart of a vehicle steep slope descent control method according to a specific embodiment of the present application. Figure 1 As shown, the vehicle steep slope descent control method 100 may include the following steps:

[0063] In step S110, when the vehicle is in a state of slowly descending a steep slope, the slip ratio of the vehicle is obtained.

[0064] In step S120, when the slip ratio of the vehicle is greater than a preset slip ratio, the vehicle is controlled to enter an anti-lock braking state so that the slip ratio of the vehicle decreases to not greater than the preset slip ratio.

[0065] In an embodiment of the present application, when the vehicle is in a steep slope descent state, the driver does not need to manually brake the vehicle, and the vehicle can automatically brake so that the vehicle travels at a constant speed during the downhill process, thereby improving the driving stability of the vehicle during the downhill process. At this time, the slip rate of the vehicle is obtained. Exemplarily, the slip rate of the vehicle refers to the proportion of the sliding cost in the wheel movement. Too large a slip rate will cause the vehicle to easily slip, drift, and lose steering control. When the slip rate of the vehicle is 100%, it represents pure sliding of the wheel lock. When the detected slip rate of the vehicle is greater than the preset slip rate, the vehicle is immediately controlled to enter the anti-lock state so that the slip rate of the vehicle drops to no more than the preset slip rate. Exemplarily, the appropriate range of values ​​of the preset slip rate should be selected according to the actual situation. Exemplarily, the preset slip rate is 15%. When the slip rate of the vehicle is no more than 15%, there is good longitudinal and lateral adhesion between the wheel and the road surface.

[0066] Therefore, the vehicle steep slope descent control method of the embodiment of the present application can obtain the vehicle's slip rate when the vehicle is in a steep slope descent state, and when the vehicle's slip rate is greater than a preset slip rate, control the vehicle to enter an anti-lock braking state, so that the vehicle's slip rate drops to no more than the preset slip rate, so that when the vehicle is in a steep slope descent state, the vehicle's slip rate can be always controlled within a safe range, maintaining the vehicle's stable driving, and preventing the vehicle from falling into a dangerous condition due to an excessively large slip rate, thereby greatly improving the safety performance.

[0067] In one example, before the vehicle is in the steep slope descent state, the method further includes: when a steep slope descent standby condition is met, controlling the vehicle to enter the steep slope descent standby state from the steep slope descent off state.

[0068] In one example, the steep slope descent standby condition includes: the vehicle's braking system has no faults; the steep slope descent switch is in the on state; the vehicle's speed is less than the first speed. Exemplarily, a steep slope descent switch is provided in the vehicle, and the steep slope descent switch is in the off state by default in the power-on state, that is, the vehicle is in the steep slope descent off state by default, and if the vehicle is to enter the steep slope descent standby state from the steep slope descent off state, the driver or other operator needs to manually open the steep slope descent switch to make the steep slope descent switch in the on state, and at the same time, it is necessary to ensure that the vehicle's braking system has no faults and the vehicle's speed is less than the first speed. When the braking system fails or the vehicle speed is greater than the first speed, even if the steep slope descent switch is in the on state, the vehicle cannot enter the steep slope descent standby state. Exemplarily, the vehicle being in the steep slope descent standby state is one of the conditions for whether the subsequent vehicle can enter the steep slope descent state, that is, only when the vehicle is in the steep slope descent standby state and meets the steep slope descent intervention conditions below, the vehicle can enter the steep slope descent state to brake the vehicle. Exemplarily, a suitable value range of the first vehicle speed should be selected according to actual conditions. In this embodiment, the first vehicle speed is 60 km / h.

[0069] In one example, the method further includes: when the vehicle is in a steep slope descent standby state, when a steep slope descent intervention condition is met, controlling the vehicle to enter a steep slope descent state to brake the vehicle.

[0070] In one example, the steep slope descent intervention condition includes: the vehicle speed is not less than the second speed and not greater than the third speed; the slope of the vehicle's driving road is less than the first slope; the throttle operation signal and the brake pedal operation signal are not received. Exemplarily, the vehicle can only be controlled to enter the steep slope descent state when the vehicle is in the steep slope descent standby state and meets the steep slope descent intervention condition. Exemplarily, the second speed is the maximum speed that can be reached when the vehicle's gear is the driving (D) gear or the reverse (R) gear and idling on a single high-adhesion horizontal road surface, and its size is related to the specific vehicle model, mode and gear position. Exemplarily, the first speed is 8km / h. Exemplarily, the third speed is greater than the second speed, and the third speed is 38km / h. Exemplarily, the third speed is less than the first speed. Exemplarily, the slope of the vehicle's driving road can be calculated by collecting the acceleration of the vehicle. Exemplarily, the first slope is 6%. Exemplarily, the failure to receive the accelerator operation signal and the brake pedal operation signal represents that the accelerator and the brake pedal are not pressed. Exemplarily, the accelerator operation signal includes an accelerator depth signal, and the brake pedal operation signal includes a brake pedal depth signal. When the accelerator and the brake pedal are not pressed, the accelerator depth signal and the brake pedal depth signal are 0.

[0071] In one example, the controlling the vehicle to enter a steep slope descent state includes: obtaining a steep slope descent speed according to the vehicle speed and the slope of the road on which the vehicle is traveling; and controlling the vehicle so that the difference between the vehicle speed and the steep slope descent speed is lower than a preset speed difference. Exemplarily, the preset speed difference is 0.5 km / h. Exemplarily, when the fourth vehicle speed and the second slope are constantly changing, the obtained steep slope descent speed is also constantly changing.

[0072] In one example, controlling the vehicle so that the difference between the vehicle speed and the steep slope descent speed is lower than a preset speed difference includes: braking the vehicle through a motor feedback braking mode so that the difference between the vehicle speed and the steep slope descent speed is lower than a preset speed difference; or braking the vehicle through a motor feedback and hydraulic hybrid braking mode so that the difference between the vehicle speed and the steep slope descent speed is lower than a preset speed difference. Exemplarily, by obtaining the steep slope descent speed, the target braking torque required for braking the vehicle can be obtained based on the fourth speed and the steep slope descent speed, the fourth speed is the current speed of the vehicle, and the target braking torque is the torque required to change the vehicle speed from the current speed to the steep slope descent speed. Exemplarily, the target braking torque can be calculated based on the current vehicle speed and the steep slope descent speed through an incremental PID algorithm. Exemplarily, in the motor feedback braking mode, part of the mechanical energy of the vehicle (e.g., kinetic energy or potential energy) can be converted into other forms of energy (e.g., electrical energy) and stored in an energy storage device (e.g., a battery, a supercapacitor or an ultra-high-speed flywheel, etc.) to achieve the purpose of recovering braking energy. At the same time, the vehicle can be braked by applying the motor feedback torque to the drive shaft. Exemplarily, when the motor feedback braking mode alone can provide a torque that meets the target braking torque, the motor feedback braking mode can be used alone to brake the vehicle, thereby improving the energy recovery efficiency and the economy of the vehicle. At the same time, because the hydraulic braking mode is not required to be used additionally, the working frequency and intensity of the brake disc can be reduced, greatly improving the service life. Exemplarily, when the motor feedback braking mode alone cannot provide a torque that meets the target braking torque, the hydraulic braking mode is used additionally to brake the vehicle, that is, the motor feedback and hydraulic hybrid braking mode is used to brake the vehicle. Exemplarily, the hydraulic braking mode only needs to provide a torque equal to the difference between the target braking torque and the maximum torque that the motor feedback braking mode can provide. Exemplarily, in the hydraulic braking mode, the vehicle is braked by adjusting the vehicle speed by adjusting the pressure-increasing valve and the pressure-releasing valve.

[0073] In one example, when the vehicle is in the anti-lock state, the vehicle can be controlled to reduce the slip rate of the vehicle to no more than a preset slip rate, and when the slip rate of the vehicle is reduced to no more than the preset slip rate, the vehicle is controlled to exit the anti-lock state. Exemplarily, the anti-lock state and the steep slope descent state can coexist, that is, the vehicle can be in the anti-lock state and the steep slope descent state at the same time.

[0074] In one example, it also includes: when the vehicle is in the steep slope descent state, when the steep slope descent return condition is met, the vehicle is controlled to return from the steep slope descent state to the steep slope descent standby state; wherein the steep slope descent state return condition includes: the vehicle speed is less than the second vehicle speed; or the throttle operation signal or the brake pedal operation signal is received. Exemplarily, after the vehicle returns from the steep slope descent state to the steep slope descent standby state, if the steep slope descent intervention condition is met, the vehicle will enter the steep slope descent state from the steep slope descent standby state. Exemplarily, when the vehicle is in the steep slope descent state, when the brake pedal operation signal is received, that is, the brake pedal is stepped on, because the master cylinder pressure needs to be released first, and then the braking strength is judged according to the brake pedal stroke and speed, the action of the vehicle returning from the steep slope descent state to the steep slope descent standby state will have a certain delay, and it is also normal that the brake pedal is briefly stepped on but the vehicle does not return to the steep slope descent standby state. For example, when the vehicle is in the steep slope descent state, when the driver wants to change the speed, he will step on the accelerator or brake pedal, and the vehicle will return to the steep slope descent standby state. When the driver releases the accelerator and brake pedals, if the remaining conditions of the steep slope descent intervention are met at the same time, the vehicle will automatically enter the steep slope descent state.

[0075] In one example, the method further includes: when the vehicle is in a steep slope descent state, when a steep slope descent exit condition is met, controlling the vehicle to exit from the steep slope descent state to a steep slope descent off state; wherein the steep slope descent state exit condition includes: a steep slope descent switch is in an off state. Exemplarily, when the vehicle is in a steep slope descent state, if the driver or other operator directly turns off the steep slope descent switch, the vehicle will directly exit to the steep slope descent off state.

[0076] In one example, it also includes: when the vehicle is in the steep slope descent standby state, when the steep slope descent standby state exit condition is met, the vehicle is controlled to exit the steep slope descent standby state; wherein the steep slope descent standby state exit condition includes: the vehicle speed is greater than the first vehicle speed; or the steep slope descent switch is in the off state. Exemplarily, when the vehicle is in the steep slope descent standby state, when the steep slope descent standby state exit condition is met, the vehicle is controlled to exit from the steep slope descent standby state to the steep slope descent off state, and when the steep slope descent standby condition is met, the vehicle enters the steep slope descent standby state from the steep slope descent off state. Exemplarily, the vehicle can directly perform a two-way switch between the steep slope descent off state and the steep slope descent standby state, and the vehicle can also directly perform a two-way switch between the steep slope descent standby state and the steep slope descent state, and the vehicle can also directly switch from the steep slope descent state to the steep slope descent off state, but the vehicle cannot directly switch from the steep slope descent off state to the steep slope descent state.

[0077] In one example, when the vehicle cannot be controlled to enter the steep slope descent state, it also includes: controlling the vehicle to enter the electronic parking brake state to brake the vehicle. Exemplarily, when the hydraulic braking mode or the motor feedback braking mode of the vehicle fails, the vehicle cannot be braked by hydraulic braking or motor feedback braking. At this time, the vehicle can be controlled to enter the electronic parking brake state and brake the vehicle by pure mechanical braking, for example, by pulling up the handbrake to directly control the brake shoes of the rear wheels of the vehicle through a steel wire.

[0078] In one example, controlling the vehicle to enter an anti-lock state includes: controlling wheel pressure by controlling wheel pressure holding and pressure relief valves to achieve the anti-lock state. Exemplarily, when the vehicle is in a steep slope descent state and an anti-lock state at the same time, the brake system needs to be responsible for keeping the master cylinder pressure from decreasing.

[0079] Various embodiments of the vehicle steep slope descent control method of the present application are described above by way of example. These embodiments may be freely combined. The following is an embodiment of a combination of the above embodiments.

[0080] like Figure 2 As shown, Figure 2 A schematic flow chart of a vehicle steep slope descent control method according to another specific embodiment of the present application is shown.

[0081] First, execute step S201 to confirm whether the steep slope descent control switch is in the on state. If the steep slope descent control switch is in the on state, execute step S202; if the steep slope descent control switch is not in the on state, execute step S204.

[0082] In step S202, it is confirmed whether the braking system of the vehicle has no faults. If the braking system of the vehicle has no faults, step S203 is executed; if the braking system of the vehicle has faults, step S204 is executed.

[0083] In step S203, it is confirmed whether the vehicle speed is less than 60 km / h. If the vehicle speed is less than 60 km / h, step S205 is executed; if the vehicle speed is not less than 60 km / h, step S204 is executed.

[0084] In step S204, the vehicle is controlled to be in a hill descent control closed state.

[0085] In step S205, the vehicle is controlled to enter a steep slope descent standby state, and step S206 is executed.

[0086] In step S206, confirm whether the slope of the vehicle's driving road is greater than 6%. If the slope of the vehicle's driving road is greater than 6%, execute step S207; if the slope of the vehicle's driving road is not greater than 6%, return to step S205.

[0087] In step S207, confirm whether the vehicle speed is not greater than 38 km / h. If the vehicle speed is not greater than 38 km / h, execute step S208; if the vehicle speed is greater than 38 km / h, return to step S205.

[0088] In step S208, confirm whether the vehicle speed is not less than 8 km / h. If the vehicle speed is not less than 8 km / h, execute step S209; if the vehicle speed is less than 8 km / h, return to step S205.

[0089] In step S209, confirm whether the throttle operation signal and the brake pedal operation signal are not received. If the throttle operation signal and the brake pedal operation signal are not received, execute step S210; if the throttle operation signal or the brake pedal operation signal is received, return to step S205.

[0090] In step S210, the vehicle is controlled to enter a steep slope descent state: the current vehicle speed and slope are obtained, based on the current vehicle speed and slope, the steep slope descent speed is obtained, and step S211 is executed.

[0091] In step S211, the vehicle is controlled so that the difference between the vehicle speed and the steep slope descent speed is less than 0.5 km / h, and step S212 is executed.

[0092] In step S212, it is confirmed whether the vehicle slip ratio is greater than the preset slip ratio. If the vehicle slip ratio is greater than the preset slip ratio, step S213 is executed; if the vehicle slip ratio is not greater than the preset slip ratio, step S214 is executed.

[0093] In step S213, the vehicle is controlled to enter an anti-lock braking state. When the vehicle slip rate drops below a preset slip rate, the anti-lock braking state is exited and the process returns to step S210.

[0094] In step S214, confirm whether the vehicle speed is less than 8 km / h, and confirm whether the accelerator operation signal or the brake pedal operation signal is received. If the vehicle speed is less than 8 km / h, or the accelerator operation signal or the brake pedal operation signal is received, return to step S205.

[0095] The above describes exemplarily a vehicle steep slope descent control method of a specific embodiment of the present application. Based on the above description, the vehicle steep slope descent control method of a specific embodiment of the present application can obtain the slip rate of the vehicle when the vehicle is in a steep slope descent state, and when the slip rate of the vehicle is greater than the preset slip rate, control the vehicle to enter the anti-lock state, so that the slip rate of the vehicle is reduced to not more than the preset slip rate, so that when the vehicle is in a steep slope descent state, the vehicle slip rate can be controlled within a safe range, the vehicle is maintained to be stable, and the vehicle is prevented from falling into a dangerous working condition due to an excessive slip rate, which greatly improves the safety performance. Exemplarily, the vehicle can be braked by the motor feedback braking mode, so that part of the braking energy can be recovered, so that the energy recovery efficiency can be improved, and the economy of the vehicle can be improved. At the same time, when the motor feedback braking mode is not enough to meet the braking demand of the vehicle, the vehicle can be braked by the hydraulic braking mode, which can ensure that the vehicle has sufficient braking force, and the comfort and safety are improved. For example, when it is impossible to enter the steep slope descent state, the vehicle can also be controlled to enter the electronic parking brake state to brake the vehicle, providing another layer of protection for vehicle braking and further improving safety.

[0096] Below, refer to Figure 3 To describe the controller of the present application. Figure 3 FIG. 1 shows a schematic structural block diagram of a controller according to a specific embodiment of the present application. Figure 3 As shown, the controller 300 includes a processor 310 and a memory 320. The memory 320 stores a computer program. When the computer program is executed by the processor 310, the processor 310 executes the intelligent driving method described above.

[0097] Below, refer to Figure 4 To describe a vehicle steep slope descent control system according to a specific embodiment of the present application, Figure 4 A schematic structural block diagram of a vehicle steep slope descent control system according to a specific embodiment of the present application is shown.

[0098] like Figure 4As shown, the control system 400 for the vehicle's steep slope descent comprises an anti-lock braking system 410 and the above-mentioned controller 300, wherein: the controller 300 is used to obtain the slip rate of the vehicle when the vehicle is in a steep slope descent state; the controller 300 is also used to control the vehicle to enter an anti-lock state when the slip rate of the vehicle is greater than a preset slip rate: the controller 300 controls the anti-lock braking system 410 to perform anti-lock braking on the vehicle so that the slip rate of the vehicle drops to no more than the preset slip rate.

[0099] In an embodiment of the present application, when the vehicle is in a steep slope descent state, the driver does not need to manually brake the vehicle, and the vehicle can automatically brake so that the vehicle travels at a constant speed during the downhill process, thereby improving the driving stability of the vehicle during the downhill process. At this time, the slip rate of the vehicle is obtained. Exemplarily, the slip rate of the vehicle refers to the proportion of the sliding cost in the wheel movement. Excessive slip rate will cause the vehicle to easily slip, drift, and lose steering control. When the slip rate of the vehicle is 100%, it represents pure sliding of the wheel lock. When the detected slip rate of the vehicle is greater than the preset slip rate, the vehicle is immediately controlled to enter the anti-lock state so that the slip rate of the vehicle drops to no more than the preset slip rate. Exemplarily, the appropriate range of values ​​of the preset slip rate should be selected according to the actual situation. Exemplarily, the preset slip rate is 15%. When the slip rate of the vehicle is no more than 15%, there is good longitudinal and lateral adhesion between the wheel and the road surface. Exemplarily, the controller 300 can be a rear body domain controller.

[0100] Therefore, in the control system of the vehicle steep slope descent in the embodiment of the present application, the controller can obtain the slip rate of the vehicle when the vehicle is in the steep slope descent state, and control the vehicle to enter the anti-lock state when the slip rate of the vehicle is greater than the preset slip rate: the controller controls the anti-lock braking system to perform anti-lock braking on the vehicle to reduce the slip rate of the vehicle to no more than the preset slip rate, so that when the vehicle is in the steep slope descent state, the vehicle slip rate can be controlled within a safe range at all times, the vehicle's stable driving can be maintained, and the vehicle can be prevented from falling into a dangerous condition due to an excessively large slip rate, thereby greatly improving the safety performance.

[0101] In one example, the control system 400 further includes a braking system 420. Before the vehicle is in the steep slope descent state, when the steep slope descent standby condition is met, the controller 300 controls the vehicle to enter the steep slope descent standby state from the steep slope descent off state; wherein the steep slope descent standby condition includes: the braking system 420 is fault-free; the steep slope descent switch is in the on state; and the vehicle speed is less than the first vehicle speed. Exemplarily, a steep slope descent switch is provided in the vehicle, and the steep slope descent switch is in the off state by default in the power-on state, that is, the vehicle is in the steep slope descent off state by default. If the vehicle is to enter the steep slope descent standby state from the steep slope descent off state, the driver or other operator needs to manually turn on the steep slope descent switch to turn the steep slope descent switch on, and at the same time, it is necessary to ensure that the braking system 420 is fault-free and the vehicle speed is less than the first vehicle speed. When the braking system 420 fails or the vehicle speed is greater than the first vehicle speed, even if the steep slope descent switch is in the on state, the vehicle cannot enter the steep slope descent standby state. Exemplarily, the vehicle being in the steep slope descent standby state is one of the conditions for whether the subsequent vehicle can enter the steep slope descent state, that is, only when the vehicle is in the steep slope descent standby state and meets the steep slope descent intervention conditions below, the vehicle can enter the steep slope descent state to brake the vehicle. Exemplarily, the appropriate range of values ​​of the first vehicle speed should be selected according to actual conditions. In this embodiment, the first vehicle speed is 60km / h. Exemplarily, the braking system 420 can be an intelligent power braking system or a Fudi power braking safety control system.

[0102] In one example, when the vehicle is in the steep slope descent standby state, when the steep slope descent intervention condition is met, the controller 300 controls the vehicle to enter the steep slope descent state: the controller 300 controls the braking system 420 to brake the vehicle; wherein the steep slope descent intervention condition includes: the vehicle speed is not less than the second vehicle speed and not greater than the third vehicle speed; the slope of the vehicle's driving road is less than the first slope; the throttle operation signal and the brake pedal operation signal are not received. Exemplarily, only when the vehicle is in the steep slope descent standby state and the steep slope descent intervention condition is met, the controller 300 can control the vehicle to enter the steep slope descent state. Exemplarily, the second vehicle speed is the maximum vehicle speed that can be reached when the vehicle's gear is the driving (D) gear or the reverse (R) gear and idling on a single high-adhesion horizontal road surface, and its size is related to the specific vehicle model, mode and gear position of the vehicle. Exemplarily, the first vehicle speed is 8km / h. Exemplarily, the third vehicle speed is greater than the second vehicle speed, and the third vehicle speed is 38km / h. Exemplarily, the third vehicle speed is less than the first vehicle speed. Exemplarily, the slope of the vehicle's driving road can be calculated by collecting the acceleration of the vehicle. Exemplarily, the first slope is 6%. Exemplarily, the failure to receive the throttle operation signal and the brake pedal operation signal represents that neither the throttle nor the brake pedal is stepped on. Exemplarily, the throttle operation signal includes a throttle depth signal, and the brake pedal operation signal includes a brake pedal depth signal. When the throttle and the brake pedal are not stepped on, the throttle depth signal and the brake pedal depth signal are 0. Exemplarily, the controller 300 is connected to the throttle and the brake pedal, and is used to receive the throttle operation signal and the brake pedal operation signal.

[0103] In one example, the controller 300 controls the vehicle to enter a steep slope descent state, including: the controller 300 obtains a steep slope descent speed according to the vehicle speed and the slope of the vehicle's driving road; under the control of the controller 300, the braking system 420 controls the vehicle so that the difference between the vehicle speed and the steep slope descent speed is lower than a preset speed difference. Exemplarily, the preset speed difference is 0.5 km / h. Exemplarily, when the fourth vehicle speed and the second slope are constantly changing, the obtained steep slope descent speed is also constantly changing.

[0104] In one example, the braking system 420 controls the vehicle so that the difference between the vehicle speed and the steep slope descent speed is lower than the preset speed difference, including: the braking system 420 brakes the vehicle through a motor feedback braking mode so that the difference between the vehicle speed and the steep slope descent speed is lower than the preset speed difference; or, the braking system 420 brakes the vehicle through a motor feedback and hydraulic hybrid braking mode so that the difference between the vehicle speed and the steep slope descent speed is lower than the preset speed difference. Exemplarily, by obtaining the steep slope descent speed, the target braking torque required for braking the vehicle can be obtained based on the fourth speed and the steep slope descent speed, the fourth speed is the current speed of the vehicle, and the target braking torque is the torque required to change the vehicle speed from the current speed to the steep slope descent speed. Exemplarily, the target braking torque can be calculated based on the current vehicle speed and the steep slope descent speed through an incremental PID algorithm. Exemplarily, in the motor feedback braking mode, part of the mechanical energy of the vehicle (e.g., kinetic energy or potential energy) can be converted into other forms of energy (e.g., electrical energy) and stored in an energy storage device (e.g., a battery, a supercapacitor or an ultra-high-speed flywheel, etc.) to achieve the purpose of recovering braking energy. At the same time, the vehicle can be braked by applying the motor feedback torque to the drive shaft. Exemplarily, when the motor feedback braking mode alone can provide a torque that meets the target braking torque, the motor feedback braking mode can be used alone to brake the vehicle, thereby improving the energy recovery efficiency and the economy of the vehicle. At the same time, because the hydraulic braking mode is not required to be used additionally, the working frequency and intensity of the brake disc can be reduced, greatly improving the service life. Exemplarily, when the motor feedback braking mode alone cannot provide a torque that meets the target braking torque, the hydraulic braking mode is used additionally to brake the vehicle, that is, the motor feedback and hydraulic hybrid braking mode is used to brake the vehicle. Exemplarily, the hydraulic braking mode only needs to provide a torque equal to the difference between the target braking torque and the maximum torque that the motor feedback braking mode can provide. For example, in the hydraulic braking mode, the braking system 420 can brake the vehicle by adjusting the vehicle speed by adjusting the boost valve and the pressure relief valve.

[0105] In one example, when the vehicle is in the anti-lock state, under the control of the controller 300, the anti-lock braking system 410 can control the vehicle to reduce the slip rate of the vehicle to no more than a preset slip rate, and when the slip rate of the vehicle is reduced to no more than the preset slip rate, the controller 300 controls the vehicle to exit the anti-lock state. Exemplarily, the anti-lock state and the steep slope descent state can coexist, that is, the vehicle can be in the anti-lock state and the steep slope descent state at the same time.

[0106] In one example, when the vehicle is in a steep slope descent state, when the steep slope descent return condition is met, the controller 300 controls the vehicle to return from the steep slope descent state to the steep slope descent standby state; wherein the steep slope descent state return condition includes: the vehicle speed is less than the second vehicle speed; or the throttle operation signal or the brake pedal operation signal is received. Exemplarily, after the vehicle returns from the steep slope descent state to the steep slope descent standby state, if the steep slope descent intervention condition is met again, the vehicle will enter the steep slope descent state from the steep slope descent standby state. Exemplarily, when the vehicle is in a steep slope descent state, when the brake pedal operation signal is received, that is, when the brake pedal is stepped on, because the master cylinder pressure needs to be released first, and then the braking strength is determined according to the brake pedal stroke and speed, the vehicle will return from the steep slope descent state to the steep slope descent standby state. There will be a certain delay in the action, and it is also normal that the vehicle does not return to the steep slope descent standby state when the brake pedal is stepped on briefly. For example, when the vehicle is in the steep slope descent state, when the driver wants to change the speed, he will step on the accelerator or brake pedal, and the vehicle will return to the steep slope descent standby state. When the driver releases the accelerator and brake pedals, if the remaining part of the steep slope descent intervention conditions are met at the same time, the controller 300 will control the vehicle to automatically enter the steep slope descent state.

[0107] In one example, when the vehicle is in a steep slope descent state, when a steep slope descent exit condition is met, the controller 300 controls the vehicle to exit from the steep slope descent state to a steep slope descent off state; wherein the steep slope descent state exit condition includes: a steep slope descent switch is in an off state. Exemplarily, when the vehicle is in a steep slope descent state, if the driver or other operator directly turns off the steep slope descent switch, the vehicle will directly exit to the steep slope descent off state.

[0108] In one example, when the vehicle is in the steep slope descent standby state, when the steep slope descent standby state exit condition is met, the controller 300 controls the vehicle to exit the steep slope descent standby state; wherein the steep slope descent standby state exit condition includes: the vehicle speed is greater than the first vehicle speed; or the steep slope descent switch is in the off state. Exemplarily, when the vehicle is in the steep slope descent standby state, when the steep slope descent standby state exit condition is met, the controller 300 controls the vehicle to exit from the steep slope descent standby state to the steep slope descent off state, and when the steep slope descent standby condition is met again, the controller 300 controls the vehicle to enter the steep slope descent standby state from the steep slope descent off state. Exemplarily, the vehicle can directly switch in both directions between the steep hill descent control off state and the steep hill descent control standby state, the vehicle can also directly switch in both directions between the steep hill descent control standby state and the steep hill descent control state, and the vehicle can also switch directly from the steep hill descent control state to the steep hill descent control off state, but the vehicle cannot directly switch directly from the steep hill descent control off state to the steep hill descent control state.

[0109] In one example, the control system 400 further includes an electronic parking brake system 430. When the controller 300 cannot control the vehicle to enter a steep slope descent state, the controller 300 controls the vehicle to enter an electronic parking brake state: the controller 300 controls the electronic parking brake system 430 to brake the vehicle. Exemplarily, when the hydraulic braking mode or the motor feedback braking mode of the vehicle fails, the vehicle cannot be braked by hydraulic braking or motor feedback braking. At this time, the controller 300 can control the vehicle to enter an electronic parking brake state. Under the control of the controller 300, the electronic parking brake system 430 can brake the vehicle by pure mechanical braking, for example, by pulling up the handbrake to directly control the brake shoes of the rear wheels of the vehicle through a steel wire.

[0110] In one example, the controller 300 controls the vehicle to enter an anti-lock state, including: the controller controls the anti-lock braking system to control the wheel side pressure holding and the pressure relief valve to control the wheel side pressure to achieve the anti-lock state. Exemplarily, when the vehicle is in a steep slope descent state and an anti-lock state at the same time, the braking system needs to be responsible for keeping the master cylinder pressure from decreasing.

[0111] The above describes exemplarily a control system for a vehicle on a steep slope descent of a specific embodiment of the present application. Based on the above description, in a control system for a vehicle on a steep slope descent of a specific embodiment of the present application, the controller can obtain the slip rate of the vehicle when the vehicle is in a steep slope descent state, and when the slip rate of the vehicle is greater than a preset slip rate, control the vehicle to enter an anti-lock state: the controller controls the anti-lock braking system to perform anti-lock braking on the vehicle, so that the slip rate of the vehicle is reduced to not greater than the preset slip rate, so that when the vehicle is in a steep slope descent state, the slip rate of the vehicle can be controlled within a safe range, the stable driving of the vehicle is maintained, and the vehicle is prevented from falling into a dangerous working condition due to an excessive slip rate, which greatly improves the safety performance. Exemplarily, the braking system can brake the vehicle through a motor feedback braking mode, thereby recovering part of the braking energy, thereby improving the energy recovery efficiency and improving the economy of the vehicle. At the same time, when the motor feedback braking mode is insufficient to meet the braking demand of the vehicle, the braking system brakes the vehicle through an additional hydraulic braking mode, which can ensure that the vehicle has sufficient braking force, and the comfort and safety are improved. For example, when the controller cannot control the vehicle to enter the steep slope descent state, the controller can also control the vehicle to enter the electronic parking brake state: the controller controls the electronic parking brake system to brake the vehicle, providing another layer of protection for vehicle braking and further improving safety.

[0112] An embodiment of the present application also provides a vehicle, which includes the controller described above, or includes the vehicle steep slope descent control system described above.

[0113] Exemplarily, the vehicle also includes other components, such as a signal transmission system for signal transmission, etc., which is not limited in the embodiments of the present application.

[0114] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present invention thereto. Various changes and modifications may be made therein by one of ordinary skill in the art without departing from the scope and spirit of the present invention. All such changes and modifications are intended to be included within the scope of the present invention as required by the appended claims.

[0115] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can 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.

[0116] In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0117] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0118] Similarly, it should be understood that in order to streamline the present invention and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present invention should not be interpreted as reflecting the following intention: the claimed invention requires more features than the features explicitly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present invention.

[0119] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0120] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0121] The various component embodiments of the present invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. It should be understood by those skilled in the art that a microprocessor or digital signal processor (DSP) may be used in practice to implement some or all of the functions of some modules in the article analysis device according to an embodiment of the present invention. The present invention may also be implemented as a device program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program implementing the present invention may be stored on a computer-readable medium, or may be in the form of one or more signals. Such a signal may be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0122] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc., does not indicate any order. These words may be interpreted as names.

[0123] The above is only a specific embodiment or description of a specific embodiment of the present invention, and the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A vehicle steep slope descent control method, characterized in that: include: When the vehicle is in a state of slow descent on a steep slope, obtaining a slip rate of the vehicle; When the slip ratio of the vehicle is greater than a preset slip ratio, the vehicle is controlled to enter an anti-lock braking state so that the slip ratio of the vehicle decreases to no greater than the preset slip ratio.

2. The method according to claim 1, characterized in that: Before the vehicle is in the steep slope descent state, the method includes: When the steep slope descent standby condition is met, the vehicle is controlled to enter the steep slope descent standby state from the steep slope descent off state.

3. The method according to claim 2, characterized in that The steep slope descent standby conditions include: The braking system of the vehicle is free of faults; The hill descent control switch is on; The vehicle speed of the vehicle is less than the first vehicle speed.

4. The method according to claim 3, characterized in that The first vehicle speed is 60 km / h.

5. The method according to claim 2, characterized in that: The method further comprises: When the vehicle is in the steep slope descent standby state, when a steep slope descent intervention condition is met, the vehicle is controlled to enter the steep slope descent state to brake the vehicle.

6. The method according to claim 5, characterized in that The steep slope descent intervention conditions include: The vehicle speed is not less than the second vehicle speed and not greater than the third vehicle speed; The slope of the road on which the vehicle is traveling is less than the first slope; The accelerator operation signal and the brake pedal operation signal are not received.

7. The method according to claim 6, characterized in that The third vehicle speed is 38 km / h.

8. The method according to claim 6, characterized in that The first slope is 6%.

9. The method according to claim 1, characterized in that: The controlling the vehicle to enter the steep slope slow descent state comprises: Obtaining a steep slope descent speed according to the vehicle speed and the slope of the road on which the vehicle is traveling; The vehicle is controlled so that the difference between the vehicle speed and the steep slope descent speed is lower than a preset speed difference.

10. The method according to claim 9, characterized in that The controlling the vehicle so that the difference between the vehicle speed and the steep slope descent speed is lower than a preset speed difference includes: Braking the vehicle in a motor feedback braking mode so that the difference between the vehicle speed and the steep slope descent speed is lower than the preset speed difference; or The vehicle is braked by a motor feedback and hydraulic hybrid braking mode so that the difference between the vehicle speed and the steep slope descent speed is lower than the preset speed difference.

11. The method according to claim 1, characterized in that The method further comprises: When the slip ratio of the vehicle decreases to be no greater than the preset slip ratio, the vehicle is controlled to exit the anti-lock braking state.

12. The method according to claim 6, characterized in that The method further includes: when the vehicle is in the steep slope descent state, when a steep slope descent state return condition is met, controlling the vehicle to return from the steep slope descent state to the steep slope descent standby state; The steep slope descent state return condition includes: The vehicle speed is less than the second vehicle speed; or The throttle operation signal or the brake pedal operation signal is received.

13. The method according to claim 3, characterized in that The method further comprises: When the vehicle is in the steep slope descent control state, when a steep slope descent control state exit condition is met, controlling the vehicle to return from the steep slope descent control state to the steep slope descent control closed state; The exit conditions of the steep slope slow descent state include: The steep slope descent switch is in the off state.

14. The method according to claim 3, characterized in that The method further comprises: When the vehicle is in the steep slope descent standby state, when an exit condition of the steep slope descent standby state is met, controlling the vehicle to exit the steep slope descent standby state; The exit conditions of the steep slope descent standby state include: The vehicle speed is greater than the first vehicle speed; or The steep slope descent switch is in the off state.

15. The method according to claim 1, characterized in that When the vehicle cannot be controlled to enter the steep slope descent state, the method further includes: The vehicle is controlled to enter an electronic parking brake state to brake the vehicle.

16. The method according to claim 1, characterized in that The controlling the vehicle to enter an anti-lock braking state comprises: The anti-lock state is achieved by controlling the wheel side pressure maintaining and the pressure relief valve to control the wheel side pressure.

17. A controller, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the vehicle steep slope descent control method according to any one of claims 1 to 16.

18. A control system for a vehicle descending a steep slope, characterized in that: An anti-lock braking system comprising the controller of claim 17, wherein: The controller is further configured to control the anti-lock braking system to perform anti-lock braking on the vehicle, so that the slip rate of the vehicle is reduced to no more than the preset slip rate.

19. A vehicle, characterized in that: The vehicle includes the controller according to claim 17, or includes the control system according to claim 18.

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