Vehicle self-adaptive hybrid braking method and device, vehicle and storage medium

Abstract

The invention discloses a vehicle self-adaptive hybrid braking method and device, a vehicle and a storage medium, and relates to the technical field of vehicle control, and the method comprises the steps that the required deceleration is determined according to target speed information and preset distance information between the vehicle and a front vehicle; performing real-time numerical comparison on the preset braking deceleration and the required deceleration; and controlling a hydraulic retarder, a wheel brake and an engine to brake the vehicle according to the deceleration comparison result. Based on the performance that the hydraulic retarder is fast in response, high in stability and capable of braking frequently, the hydraulic retarder can be combined for vehicle comprehensive braking control. After the current required deceleration is obtained based on the target speed information and the preset distance information, the engine, the liquid retarder and the wheel edge brake are distributed and controlled in a self-adaptive mode according to the comparison result of the required deceleration and the preset braking deceleration to conduct vehicle braking, and the purpose that the temperature of a braking system is kept normal when stable vehicle following is achieved is achieved; and the vehicle braking safety is ensured.

Description

Technical Field

[0001] The present application relates to the field of vehicle control technology, and in particular to a vehicle adaptive hybrid braking method, device, vehicle and storage medium. Background Art

[0002] With the widespread popularity and rapid advancement of intelligent assisted driving technology (ADAS) in the commercial vehicle field, the market share of adaptive cruise control function is gradually expanding because it can effectively reduce the burden on drivers during long-distance driving, especially freeing their feet, thereby significantly reducing fatigue and improving driving safety.

[0003] However, in the vehicle's adaptive cruise control system, when the vehicle is traveling uphill or downhill, especially when long-term self-braking is required, a smaller deceleration is usually required. The current adaptive cruise system mainly relies on the wheel-side braking system to perform deceleration operations. However, due to the frequent start and stop of the wheel-side braking system, its temperature can easily rise to a higher level, and this frequent temperature change will generate a large amount of heat. If this heat cannot be effectively controlled and dissipated, it will pose a greater threat to the safety of the brake actuator. That is, the existing adaptive cruise system has certain safety hazards during the braking process, which need to be solved through technical improvements.

[0004] Therefore, how to ensure the braking safety of the vehicle has become an urgent problem to be solved. Summary of the invention

[0005] The main purpose of the present application is to provide a vehicle adaptive hybrid braking method, device, vehicle and storage medium, aiming to solve the technical problem of how to ensure the braking safety of the vehicle.

[0006] To achieve the above objectives, the present application proposes a vehicle adaptive hybrid braking method, the method comprising:

[0007] Determine the required deceleration according to the target speed information and the preset distance information between the vehicle and the preceding vehicle;

[0008] Performing a real-time numerical comparison between the preset braking deceleration and the required deceleration;

[0009] The hydraulic retarder, wheel brakes and engine are controlled to brake the vehicle based on the deceleration comparison result.

[0010] In one embodiment, before comparing the preset braking deceleration with the required deceleration in real time, the method further includes:

[0011] Performing Kalman filter calculation according to the target speed information to obtain the real-time slope of the vehicle;

[0012] The preset braking acceleration is determined based on the real-time slope of the vehicle.

[0013] In one embodiment, the preset braking deceleration includes a maximum engine braking deceleration;

[0014] The step of controlling the hydraulic retarder, the wheel brake and the engine to brake the vehicle based on the deceleration comparison result comprises:

[0015] When the required deceleration is less than the maximum engine braking deceleration, the engine is controlled to perform vehicle compound braking.

[0016] In one embodiment, the preset braking deceleration further includes a maximum braking deceleration of the retarder;

[0017] The step of controlling the hydraulic retarder, the wheel brake and the engine to brake the vehicle based on the deceleration comparison result also includes:

[0018] When the required deceleration is between the maximum braking deceleration of the engine and the maximum braking deceleration of the retarder, and the current retarder torque percentage is less than a preset torque threshold, the wheel brakes are controlled to perform vehicle feedforward braking based on the required deceleration;

[0019] When the required deceleration is between the maximum braking deceleration of the engine and the maximum braking deceleration of the retarder, and the current retarder torque percentage is greater than a preset torque threshold, the hydraulic retarder is controlled to perform vehicle feedforward braking.

[0020] In one embodiment, the step of controlling the hydraulic retarder, the wheel brake and the engine to brake the vehicle based on the deceleration comparison result further includes:

[0021] When the required deceleration is greater than the maximum braking deceleration of the retarder and the current retarder torque percentage is greater than a preset torque threshold, the wheel brakes are controlled to perform vehicle feedforward braking based on the required deceleration, and the hydraulic retarder is controlled to perform vehicle feedforward braking.

[0022] In one embodiment, the step of controlling the engine to perform vehicle compound braking includes:

[0023] Determining the engine feedforward torque according to the real-time slope of the vehicle and the required deceleration;

[0024] determining an engine feedback torque based on the target speed information;

[0025] The composite braking torque corresponding to the engine is determined according to the engine feedforward torque and the engine feedback torque, and the engine is controlled by the composite braking torque to brake the vehicle.

[0026] In one embodiment, the step of controlling the hydraulic retarder to perform vehicle feedforward braking includes:

[0027] determining a retarder feedforward torque according to the required deceleration;

[0028] The vehicle brakes by controlling the hydraulic retarder via retarder feed-forward torque.

[0029] In addition, to achieve the above-mentioned purpose, the present application also proposes a vehicle adaptive hybrid braking device, the vehicle adaptive hybrid braking device comprising:

[0030] A deceleration determination module, used to determine a required deceleration according to target speed information and preset distance information from a preceding vehicle;

[0031] A braking comparison module, used for performing a real-time numerical comparison between a preset braking deceleration and the required deceleration;

[0032] The brake control module is used to control the hydraulic retarder, wheel brakes and engine to brake the vehicle based on the deceleration comparison result.

[0033] In addition, to achieve the above-mentioned objectives, the present application also proposes a vehicle, which includes: a hydraulic retarder, wheel-side brakes, an engine, a memory, a processor, and a vehicle adaptive hybrid braking program stored in the memory and executable on the processor, wherein the vehicle adaptive hybrid braking program is configured to implement the steps of the vehicle adaptive hybrid braking method as described above.

[0034] In addition, to achieve the above-mentioned purpose, the present application also provides a storage medium, on which is stored a program for implementing a vehicle adaptive hybrid braking method, and the program for implementing a vehicle adaptive hybrid braking method is executed by a processor to implement the steps of the vehicle adaptive hybrid braking method as described above.

[0035] The present application provides a vehicle adaptive hybrid braking method, device, vehicle and storage medium, the method comprising: determining the required deceleration according to the target speed information and the preset distance information with the preceding vehicle; performing a real-time numerical comparison between the preset braking deceleration and the required deceleration; and controlling the hydraulic retarder, wheel brakes and engine to brake the vehicle according to the deceleration comparison result. Based on the performance of the hydraulic retarder with fast response, high stability and frequent braking, the present application can be combined with the hydraulic retarder to perform comprehensive vehicle braking control. The present application obtains the current required deceleration based on the target speed information related to the real-time driving of the vehicle and the preset preset distance information, and then determines the preset braking deceleration in combination with the actual driving conditions of the whole vehicle, and adaptively distributes and controls the engine, retarder and wheel brakes to brake the vehicle according to the comparison result of the required deceleration and the preset braking deceleration, so as to achieve the technical effect of maintaining the normal temperature of the braking system and ensuring the braking safety of the vehicle while achieving stable following. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0038] Figure 1 This is a first flow chart of the first embodiment of the vehicle adaptive hybrid braking method of the present application;

[0039] Figure 2 This is a second flow chart of the first embodiment of the vehicle adaptive hybrid braking method of the present application;

[0040] Figure 3 This is a flow chart of a second embodiment of the vehicle adaptive hybrid braking method of the present application;

[0041] Figure 4 This is a schematic diagram of the existing braking control process of the second embodiment of the vehicle adaptive hybrid braking method of the present application;

[0042] Figure 5 This is a schematic diagram of the adaptive hybrid braking control process of the second embodiment of the vehicle adaptive hybrid braking method of the present application;

[0043] Figure 6 Provide a brief flow chart of the vehicle adaptive hybrid braking method of the present application;

[0044] Figure 7A schematic diagram of the allocation process of the brake actuator of the vehicle adaptive hybrid braking method of the present application;

[0045] Figure 8 A schematic diagram of a vehicle adaptive hybrid braking adjustment process of the vehicle adaptive hybrid braking method of the present application;

[0046] Fig. 9 This is a schematic diagram of the module structure of the vehicle adaptive hybrid braking device according to an embodiment of the present application;

[0047] Fig.10 Schematic diagram of the device structure of the hardware operating environment involved in the vehicle adaptive hybrid braking method in the embodiment of the present application.

[0048] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0049] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0050] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0051] The main solution of this application is: determine the required deceleration based on the target speed information and the preset distance information between the vehicle in front; perform real-time numerical comparison of the preset braking deceleration and the required deceleration; and control the hydraulic retarder, wheel brakes and engine to brake the vehicle based on the deceleration comparison result.

[0052] At present, the vehicle needs to brake frequently and continuously on uphill and downhill sections. Since most commercial vehicles are heavy trucks, long-distance continuous deceleration requires a large braking torque. For such long-distance and heavy-load deceleration conditions, the existing adaptive cruise function simply controls the wheel brakes to provide braking torque, which will generate a lot of heat during the braking process and cause great safety hazards.

[0053] In view of the shortcomings of the existing wheel-side braking system, the present application uses a hydraulic retarder braking system as an auxiliary brake in the adaptive cruise function of heavy trucks. The braking system has fast response, high stability, and can adapt to continuous and frequent braking on long uphill sections. Therefore, the present application can be combined with a hydraulic retarder to perform comprehensive vehicle braking control. Specifically, the corresponding required deceleration is obtained based on the real-time driving speed information of the vehicle and the pre-set preset distance information, and then the preset braking deceleration is determined in combination with the actual use conditions of the retarder of the whole vehicle. The engine, retarder and wheel-side brakes are adaptively and reasonably allocated to control the vehicle braking according to the comparison result of the required deceleration and the preset braking deceleration, so as to achieve the technical effect of maintaining the normal temperature of the braking system while achieving stable following and ensuring the braking safety of the vehicle.

[0054] It should be noted that the execution subject of this embodiment may be an ACC (Adaptive Cruise Control) of a vehicle's adaptive hybrid braking, or a vehicle capable of realizing the above functions, etc., and this embodiment does not specifically limit this. The following takes ACC as an execution subject as an example to illustrate this embodiment and the following embodiments.

[0055] Based on this, the embodiment of the present application provides a vehicle adaptive hybrid braking method, referring to Figure 1 , Figure 1 This is a first flow chart of the first embodiment of the vehicle adaptive hybrid braking method of the present application.

[0056] In this embodiment, the vehicle adaptive hybrid braking method includes steps S10 to S30:

[0057] Step S10, determining the required deceleration according to the target speed information and the preset distance information between the vehicle and the preceding vehicle;

[0058] Step S20, performing a real-time numerical comparison between the preset braking deceleration and the required deceleration;

[0059] Step S30, controlling the hydraulic retarder, wheel brakes and engine to brake the vehicle based on the deceleration comparison result.

[0060] It is understandable that the above-mentioned target speed information can be the real-time speed of the vehicle corresponding to the current vehicle, the measured acceleration of the vehicle and the speed of the vehicle in front, etc., and the preset distance information can be the distance between the vehicle and the vehicle in front and the pre-set following time distance. Then ACC can perform PID calculation based on the target speed information and the preset distance information between the vehicle and the vehicle in front to obtain the required deceleration of the vehicle to achieve stable following.

[0061] Specifically, ACC can adjust the vehicle speed according to the vehicle's real-time speed V host , the speed of the preceding vehicle V obj, the distance from the front vehicle is R obj , and the set following time TG ref , calculate the required deceleration a n , where the control model corresponding to the above PID operation can be expressed as:

[0062]

[0063] a n =P v *(v ref -v host ); (2)

[0064] It should be understood that the above formula (1) corresponds to the control inner loop of the PID operation, which can be used to obtain the control target (i.e., setting the following time distance TG ref ) Required vehicle control speed V ref ; Formula (2) corresponds to the control outer loop of PID operation, and the result is the required deceleration a n ; and the above K p , K d , K i , P v It is a calibrable quantity for PID control and can be determined according to actual conditions.

[0065] It should be noted that, in order to ensure the braking safety of the vehicle, compared with the existing adaptive braking method that performs braking control based solely on wheel-side brakes, a hydraulic retarder is additionally installed in this embodiment, and the hydraulic retarder braking system is used as an auxiliary brake in the adaptive cruise function. It is understandable that the hydraulic retarder has a fast response and high stability, and can adapt to continuous and frequent braking on long uphill sections. Therefore, after obtaining the corresponding required deceleration based on the target speed information corresponding to the real-time driving of the vehicle and the pre-set preset distance information, the present application can be combined with the preset braking deceleration determined according to the real-time driving conditions of the whole vehicle, and adaptively distribute and control the engine, retarder and wheel-side brakes to brake the vehicle according to the comparison result of the required deceleration and the preset braking deceleration, so as to achieve the technical effect of maintaining the normal temperature of the braking system while achieving stable following and ensuring the braking safety of the vehicle.

[0066] In one possible implementation, refer to Figure 2 , Figure 2 This is a second flow chart of the first embodiment of the vehicle adaptive hybrid braking method of the present application. In this embodiment, steps A1 to A2 may be included before step S20:

[0067] Step A1, performing Kalman filter operation according to the target speed information to obtain the real-time slope of the vehicle;

[0068] From the above analysis, it can be seen that the preset braking deceleration in this embodiment can be a deceleration determined according to the real-time driving conditions of the vehicle. Specifically, the preset braking deceleration can be a vehicle deceleration that characterizes the maximum braking capacity of each braking device and is determined according to the predicted real-time slope of the vehicle.

[0069] For example, it is assumed that the acceleration of the vehicle obtained by the acceleration sensor of the vehicle is a sensor , the real-time speed of the vehicle is v host , then in the specific process of using Kalman filter operation to estimate the slope arc α of the vehicle, the vehicle speed corresponding to the current time k can be expressed as:

[0070] v host(k) =v host(k-1) +a host(k-1) ·T; (3)

[0071] The actual acceleration of the vehicle at the previous moment can be expressed as:

[0072] a host(k-1) =a sensor -g·sinα; (4)

[0073] Among them, v host(k-1) is the vehicle speed at the previous moment, and g is the acceleration due to gravity.

[0074] At this time, this embodiment can build a Kalman filter equation group according to the physical model represented by the above formulas (3) and (4) to solve it, and the solution result is the predicted arc α representing the slope of the vehicle.

[0075] Step A2: determining a preset braking acceleration based on the real-time slope of the vehicle.

[0076] It should be understood that the vehicle driving equation corresponding to the current vehicle can be expressed as follows:

[0077]

[0078] Among them, T tq represents the engine driving torque, i g represents the transmission ratio, i 0 Indicates the transmission ratio of the main reducer, η T1 represents the mechanical efficiency of the transmission system, r represents the effective radius of the tire (m), G represents the vehicle gravity (N), f represents the rolling resistance coefficient, and A represents the frontal area (m 2 ), C D represents the air resistance coefficient, ρ represents the air density, u r represents the relative speed (m / s), δ represents the vehicle rotation mass conversion factor, m represents the vehicle mass (kg), a represents the vehicle acceleration, and F rIndicates the resistance applied by the ACC controlled fluid retarder and wheel brake actuators.

[0079] It should be noted that, in this embodiment, the above-mentioned preset braking deceleration may include the maximum braking deceleration of the engine representing the maximum braking capacity of the engine and the maximum braking deceleration of the retarder representing the maximum braking capacity of the liquid retarder. tq =0, F r = 0, the maximum braking deceleration a that the engine can achieve can be calculated tq , which is expressed as follows:

[0080]

[0081] Substituting the car driving equation into T tq =0, That is, the maximum braking deceleration a that the retarder can achieve can be calculated rtd :

[0082]

[0083] Where, T rtd_max Indicates the maximum resistance torque of the retarder, η T2 represents the mechanical efficiency of the retarder transmission system, i 0 Indicates the transmission ratio of the final reducer.

[0084] In summary, this embodiment can determine the preset braking acceleration used to divide different braking modes according to the predicted real-time vehicle slope, thereby further improving the accuracy of real-time stable following.

[0085] In this embodiment, compared with the existing vehicle adaptive cruise function that uses the engine alone and the wheel-side braking system to perform deceleration, the additional addition of a retarder as an auxiliary brake actuator can reduce the braking pressure of the wheel-side braking system and make it easier to keep the temperature of the wheel-side braking system stable.

[0086] In addition, this embodiment predicts the slope of the ego vehicle and calculates the required deceleration required for following the vehicle based on the target speed information and the preset distance information between the ego vehicle and the vehicle in front. Finally, the preset braking deceleration estimated based on the slope of the vehicle is adaptively allocated to the vehicle engine, hydraulic retarder and wheel brakes for braking control, thereby allowing the ego vehicle to follow the vehicle stably while keeping the temperature of the brake actuator stable.

[0087] The present embodiment provides a vehicle adaptive hybrid braking method, the method comprising: determining the required deceleration according to the target speed information and the preset distance information from the preceding vehicle; performing Kalman filtering operation according to the target speed information to obtain the real-time slope of the vehicle; and determining the preset braking acceleration based on the real-time slope of the vehicle. Performing a real-time numerical comparison between the preset braking deceleration and the required deceleration; and controlling the hydraulic retarder, wheel-side brakes, and engine to brake the vehicle based on the deceleration comparison result. Compared with the existing vehicle adaptive cruise function that uses the engine alone and the wheel-side brake system to perform deceleration, the additional addition of a retarder as an auxiliary brake actuator can reduce the braking pressure of the wheel-side brake system and make it easier to keep the temperature of the wheel-side brake system stable.

[0088] In addition, this embodiment predicts the slope of the ego vehicle and calculates the required deceleration required for following the vehicle based on the target speed information and the preset distance information between the ego vehicle and the vehicle in front. Finally, the preset braking deceleration estimated based on the slope of the vehicle is adaptively allocated to the vehicle engine, hydraulic retarder and wheel brakes for braking control, thereby allowing the ego vehicle to follow the vehicle stably while keeping the temperature of the brake actuator stable.

[0089] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction and will not be repeated later.

[0090] Based on the first embodiment, please refer to Figure 3 , Figure 3 This is a flow chart of the second embodiment of the vehicle adaptive hybrid braking method of the present application. In this embodiment, in a first feasible implementation, step S30 includes step B1:

[0091] Step B1, when the required deceleration is less than the maximum braking deceleration of the engine, controlling the engine to perform vehicle compound braking.

[0092] It is easy to understand that, combined with the above analysis, this embodiment can control different deceleration actuators to brake the vehicle according to the comparison result between the required deceleration and the preset braking deceleration. n Less than the maximum braking deceleration a that the engine can provide tq , then ACC can decelerate through the engine and put the vehicle in a coasting state.

[0093] It should be noted that the present embodiment is different from the prior art in that, in the process of performing brake control on the engine, the liquid retarder and the wheel brake, the brake actuator controller calculates the control torque or deceleration corresponding to each deceleration actuator according to the required deceleration during the prior art brake control, and then distributes the torque or deceleration to brake the vehicle. Therefore, even if a liquid retarder is built on the basis of the prior art, the corresponding deceleration actuator control distribution process can refer to Figure 4 , Figure 4 This is a schematic diagram of the existing braking control process of the second embodiment of the vehicle adaptive hybrid braking method of the present application, that is, the processing logic of the deceleration actuator call in the prior art is performed at the brake actuator controller end, and the brake actuator calculates and distributes the required torque of the retarder and the engine and the deceleration required by the wheel-side brake actuator; when the present application performs braking control, the torque distribution corresponding to the liquid retarder and the deceleration distribution corresponding to the wheel-side brake are placed in the adaptive feedforward control process, and the torque distribution corresponding to the engine is placed in the composite control process composed of feedforward control and feedback control. The specific process can be referred to Figure 5 , Figure 5 This is a schematic diagram of the adaptive hybrid braking control process of the second embodiment of the vehicle adaptive hybrid braking method of the present application.

[0094] As an implementable method, in this embodiment, step B1 includes steps B11 to B13:

[0095] Step B11, determining the engine feedforward torque according to the real-time slope of the vehicle and the required deceleration;

[0096] Step B12, determining the engine feedback torque based on the target speed information;

[0097] Step B13, determining the composite braking torque corresponding to the engine according to the engine feedforward torque and the engine feedback torque, and controlling the engine to brake the vehicle through the composite braking torque.

[0098] It is easy to understand that Figure 5 It can be seen that in this embodiment, ACC calculates the required deceleration of the vehicle according to the slope of the vehicle, the speed of the vehicle, the speed of the transmission shaft and other information, and then determines the corresponding distribution processing results of the engine, liquid retarder and wheel brake according to the required acceleration and deceleration. When the distribution processing result is that the engine brakes the vehicle, the engine feedforward torque can be calculated first, and then the engine feedback torque can be calculated according to the actual acceleration of the vehicle in the target speed information, and then the engine feedforward torque and the engine feedback torque are added to obtain the composite braking torque required to be provided when the engine is braked.

[0099] According to formula (5), substitute the required deceleration a into n 、Trtd = 0, combined with the predicted real-time slope α of the vehicle, the engine feedforward torque T can be calculated tq , and expressed as:

[0100]

[0101] At this time, the retarder required torque T allocated by ACC rtd =0, wheel brake required deceleration a XBR =0.

[0102] In a second feasible implementation manner, in this embodiment, the preset braking deceleration also includes the maximum braking deceleration of the retarder; step S30 may also include steps C1 to C2:

[0103] Step C1, when the required deceleration is between the maximum braking deceleration of the engine and the maximum braking deceleration of the retarder, and the current retarder torque percentage is less than a preset torque threshold, controlling the wheel brakes to perform vehicle feedforward braking based on the required deceleration;

[0104] Step C2: when the required deceleration is between the maximum braking deceleration of the engine and the maximum braking deceleration of the retarder, and the current retarder torque percentage is greater than a preset torque threshold, controlling the hydraulic retarder to perform vehicle feedforward braking.

[0105] It is easy to understand that Figure 5 It can be seen that when ACC detects that the required deceleration is between the maximum braking deceleration of the engine and the maximum braking deceleration of the retarder, and the current retarder torque percentage is less than the preset torque threshold P Thrhld (This threshold is related to the vehicle speed and the transmission shaft speed and can be provided by the vehicle signal), the determined allocation processing result is to perform vehicle feedforward braking through the wheel side brake. At this time, the required deceleration can be directly transmitted to the wheel side brake for braking, that is, the wheel side brake required deceleration a XBR =a n , retarder required resistance torque T rtd =0, engine demand torque T tq =0.

[0106] When it is detected that the required deceleration is between the maximum braking deceleration of the engine and the maximum braking deceleration of the retarder, and the current retarder torque percentage is greater than the preset torque threshold, the distribution processing result is determined to perform vehicle feedforward braking by controlling the hydraulic retarder. At this time, ACC needs to determine the torque Trt required to be transmitted to the liquid retarder for braking. d , and the wheel brake requires a deceleration XBR =0, engine demand torque T tq =0.

[0107] In a third feasible implementation manner, in this embodiment, the preset braking deceleration also includes a maximum braking deceleration of the retarder; step S30 may further include step D1:

[0108] Step D1, when the required deceleration is greater than the maximum braking deceleration of the retarder, and the current retarder torque percentage is greater than a preset torque threshold, the wheel brakes are controlled to perform vehicle feedforward braking based on the required deceleration, and the hydraulic retarder is controlled to perform vehicle feedforward braking.

[0109] It is understandable that if the required deceleration a calculated by ACC is n Greater than the maximum braking deceleration a that the retarder can provide rtd , and the retarder available torque percentage P is greater than the threshold value P Thrhld ACC can perform deceleration braking control through wheel-side brakes and retarder at the same time. The reason is that it takes a certain amount of time for the retarder to reach the required torque. Under this condition, the switching combined with wheel-side braking is faster than using retarder braking alone.

[0110] As an implementable method, in this embodiment, step C2 includes steps C21 to C22:

[0111] Step C21, determining the retarder feedforward torque according to the required deceleration;

[0112] Step C22, controlling the hydraulic retarder by retarder feedforward torque to brake the vehicle.

[0113] It should be noted that if ACC determines that the retarder is needed for braking (actually including the above-mentioned conditions of using the retarder alone for braking and the retarder and wheel brakes at the same time), then according to the vehicle driving equation, the required deceleration a is substituted n , T tq =0, the retarder feedforward torque T can be calculated rtd , and expressed as follows:

[0114]

[0115] The above are only three feasible implementation methods of step S30 provided in this embodiment, and this embodiment does not specifically limit the specific implementation method of step S30.

[0116] In summary, this embodiment proposes an adaptive cruise function for heavy trucks. After the ACC upper layer estimates the slope of the vehicle and the required deceleration in real time, it performs feedforward control on the liquid retarder and wheel brake in combination with the preset braking deceleration, and performs feedforward + feedback composite control on the engine. Therefore, this embodiment combines the feedforward control method to implement different requested torque distribution schemes for the brake actuator. Compared with the existing scheme of sending the required deceleration to the braking system and then distributing the torque by the braking system, the adaptive braking method proposed in this embodiment has better real-time performance and is easier to achieve stable following of the adaptive cruise.

[0117] The present embodiment discloses that the preset braking deceleration includes the maximum braking deceleration of the engine and the maximum braking deceleration of the retarder; when the required deceleration is less than the maximum braking deceleration of the engine, the engine feedforward torque is determined according to the real-time slope of the vehicle and the required deceleration; the engine feedback torque is determined based on the target speed information; the composite braking torque corresponding to the engine is determined according to the engine feedforward torque and the engine feedback torque, and the engine is controlled by the composite braking torque to brake the vehicle. When the required deceleration is between the maximum braking deceleration of the engine and the maximum braking deceleration of the retarder, and the current retarder torque percentage is less than the preset torque threshold, the wheel side brake is controlled based on the required deceleration to perform vehicle feedforward braking; when the required deceleration is between the maximum braking deceleration of the engine and the maximum braking deceleration of the retarder, and the current retarder torque percentage is greater than the preset torque threshold, the retarder feedforward torque is determined according to the required deceleration; the hydraulic retarder is controlled by the retarder feedforward torque to brake the vehicle. When the required deceleration is greater than the maximum braking deceleration of the retarder, and the current retarder torque percentage is greater than the preset torque threshold, the wheel brakes are controlled based on the required deceleration to perform vehicle feedforward braking, and the retarder feedforward torque is determined according to the required deceleration; the hydraulic retarder is controlled by the retarder feedforward torque to brake the vehicle. After the upper layer of this embodiment estimates the slope of the vehicle and the required deceleration in real time, it performs feedforward control on the liquid retarder and the wheel brakes, and performs feedforward + feedback composite control on the engine. Therefore, this embodiment combines the feedforward control method to implement different requested torque distribution schemes for the brake actuator. Compared with the existing scheme of sending the required deceleration to the braking system and then allocating torque by the braking system, the adaptive braking method proposed in this embodiment has better real-time performance and is easier to achieve stable following of adaptive cruise.

[0118] For example, in order to help understand the technical concept or technical principle of the vehicle adaptive hybrid braking method after the present embodiment is combined with the above-mentioned embodiment 1 and embodiment 2, please refer to Figure 6 , Figure 6 A brief flow chart of the vehicle adaptive hybrid braking method of the present application is provided, as follows:

[0119] The vehicle adaptive hybrid braking method proposed in the present application may include steps 601 to 606:

[0120] Step 601: Calculate the required deceleration according to the vehicle speed, the front vehicle speed, the distance between the vehicle and the front vehicle, and the setting of the following distance.

[0121] Step 602: Perform Kalman filtering based on the real-time speed and acceleration of the vehicle to estimate the slope of the ramp on which the vehicle is located;

[0122] Step 603: Estimating the maximum braking deceleration that the engine can provide;

[0123] Step 604: estimating the maximum braking deceleration that the retarder can provide;

[0124] Step 605: adaptively allocating corresponding brake actuators under different braking decelerations;

[0125] Step 606: Calculate the engine composite braking torque, retarder feedforward braking torque, and wheel brake required braking deceleration.

[0126] In the process of distributing the brake actuator, refer to Figure 7 , Figure 7 This is a schematic diagram of the allocation process of the brake actuator of the vehicle adaptive hybrid braking method of this application. Figure 7 As shown, if the required deceleration a calculated by ACC is n Less than the maximum braking deceleration a that the engine can provide tq , then the engine is used to decelerate and perform engine compound braking control to put the vehicle in a sliding state;

[0127] If the required deceleration a calculated by ACC n Between the maximum braking deceleration a that the engine can provide tq The maximum braking deceleration a that the retarder can provide rtd and the retarder available torque percentage P is greater than the threshold value P Thrhld , the vehicle decelerates through the retarder and performs retarder feedforward braking control;

[0128] If the required deceleration a calculated by ACC n Greater than the maximum braking deceleration a that the retarder can provide rtd , and the retarder available torque percentage P is greater than the threshold value P Thrhld , the vehicle needs to brake simultaneously through the retarder and wheel brake, and perform retarder + wheel brake feedforward braking control;

[0129] If the required deceleration a calculated by ACC n Greater than the maximum braking deceleration a that the retarder can provide rtd, and the retarder available torque percentage P is less than the threshold value P Thrhld ; or required deceleration a n At the maximum engine braking deceleration a tq Maximum braking deceleration of the retarder a rtd and the current retarder torque percentage P is less than the preset torque threshold P Thrhld When the vehicle is in a state of slowing down, it needs to decelerate through the wheel brakes alone and perform wheel brake feedforward braking control.

[0130] Therefore, assuming that the vehicle activates the adaptive cruise control function (ACC), the vehicle is equipped with a hydraulic retarder and is available, and the hydraulic retarder call switch is turned on, the ACC hardware configuration is 1V1R, the following distance is set to 2.2s, and the vehicle is driving on a downhill section with a slope of α (5%), the vehicle speed is 60kph, and the front vehicle speed is 53kph. After the front vehicle suddenly decelerates to 43kph, the vehicle braking control process of this embodiment can be as follows: Figure 8 As shown, Figure 8 This is a schematic diagram of the vehicle adaptive hybrid braking adjustment process of the vehicle adaptive hybrid braking method of the present application.

[0131] Figure 8 The parameters represented by the curves from bottom to top are slope, vehicle speed, distance to the vehicle ahead, wheel brake deceleration, retarder request torque percentage and engine request torque percentage. Figure 8 It can be seen that the adaptive braking method proposed in this application can achieve stable following after the front vehicle changes speed. By adjusting the wheel brake deceleration, retarder request torque and engine request torque, the distance between the vehicle and the front vehicle is stabilized within a range, thereby ensuring vehicle safety while achieving effective braking of the vehicle.

[0132] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the vehicle adaptive hybrid braking method of the present application. More simple transformations based on this technical concept are all within the protection scope of the present application.

[0133] This application also provides a vehicle adaptive hybrid braking device, please refer to Fig. 9 , Fig. 9 This is a schematic diagram of the module structure of the vehicle adaptive hybrid braking device according to an embodiment of the present application. In this embodiment, the vehicle adaptive hybrid braking device includes:

[0134] The deceleration determination module T1 is used to determine the required deceleration according to the target speed information and the preset distance information between the vehicle and the preceding vehicle;

[0135] A braking comparison module T2 is used to compare the preset braking deceleration with the required deceleration in real time;

[0136] The brake control module T3 is used to control the hydraulic retarder, wheel brakes and engine to brake the vehicle based on the deceleration comparison result.

[0137] Optionally, in this embodiment, the braking comparison module T2 is further used to perform a Kalman filter operation according to the target speed information to obtain the real-time slope of the vehicle;

[0138] The braking comparison module T2 is further used to determine a preset braking acceleration based on the real-time slope of the vehicle.

[0139] Optionally, in this embodiment, the preset braking deceleration includes a maximum braking deceleration of the engine;

[0140] The braking comparison module T2 is further configured to control the engine to perform vehicle compound braking when the required deceleration is less than the maximum braking deceleration of the engine.

[0141] Optionally, in this embodiment, the preset braking deceleration also includes a maximum braking deceleration of the retarder;

[0142] The braking comparison module T2 is further configured to control the wheel brakes to perform vehicle feedforward braking based on the required deceleration when the required deceleration is between the maximum braking deceleration of the engine and the maximum braking deceleration of the retarder, and the current retarder torque percentage is less than a preset torque threshold;

[0143] The braking comparison module T2 is further configured to control the hydraulic retarder to perform vehicle feedforward braking when the required deceleration is between the maximum braking deceleration of the engine and the maximum braking deceleration of the retarder, and when the current retarder torque percentage is greater than a preset torque threshold.

[0144] Optionally, in this embodiment, the braking comparison module T2 is also used to control the wheel-side brakes to perform vehicle feedforward braking based on the required deceleration, and control the hydraulic retarder to perform vehicle feedforward braking when the required deceleration is greater than the maximum braking deceleration of the retarder and the current retarder torque percentage is greater than a preset torque threshold.

[0145] Optionally, in this embodiment, the braking comparison module T2 is further used to determine the engine feedforward torque according to the real-time slope of the vehicle and the required deceleration;

[0146] The brake comparison module T2 is further used to determine the engine feedback torque based on the target speed information;

[0147] The braking comparison module T2 is further used to determine the composite braking torque corresponding to the engine according to the engine feedforward torque and the engine feedback torque, and control the engine to brake the vehicle through the composite braking torque.

[0148] Optionally, in this embodiment, the braking comparison module T2 is further used to determine the retarder feedforward torque according to the required deceleration;

[0149] The braking comparison module T2 is also used to control the hydraulic retarder to brake the vehicle through the retarder feedforward torque.

[0150] The vehicle adaptive hybrid braking device provided by the present application adopts the vehicle adaptive hybrid braking method in the above embodiment, which can solve the technical problem of how to ensure the safety of vehicle braking. Compared with the prior art, the beneficial effects of the vehicle adaptive hybrid braking device provided by the present application are the same as the beneficial effects of the vehicle adaptive hybrid braking method provided by the above embodiment, and other technical features in the vehicle adaptive hybrid braking device are the same as the features disclosed in the above embodiment method, which will not be repeated here.

[0151] The present application provides a vehicle, which includes: a hydraulic retarder, a wheel-side brake, an engine, at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the vehicle adaptive hybrid braking method in the above-mentioned embodiment one.

[0152] Reference below Fig.10 , which shows a schematic diagram of the structure of a vehicle suitable for implementing the embodiment of the present application. Fig.10As shown, the vehicle may include a processing device 1001 (e.g., a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM: Read Only Memory) 1002 or a program loaded from a storage device 1003 to a random access memory (RAM: Random Access Memory) 1004. In RAM1004, various programs and data required for vehicle operation are also stored. The processing device 1001, ROM1002, and RAM1004 are connected to each other via a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Generally, the following systems can be connected to the I / O interface 1006: an input device 1007 including, for example, a touch screen, a touch pad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; an output device 1008 including, for example, a liquid crystal display (LCD: Liquid Crystal Display), a speaker, a vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. Communication device 1009 can allow the vehicle to communicate with other devices wirelessly or by wire to exchange data; hydraulic retarder 1010; wheel brake 1011 and engine 1012. Although the figure shows a vehicle with various systems, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems can be implemented or have alternatively.

[0153] In particular, according to the embodiments disclosed in the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present application include a vehicle adaptive hybrid braking program product, which includes a vehicle adaptive hybrid braking program carried on a computer-readable medium, and the vehicle adaptive hybrid braking program contains program code for executing the method shown in the flowchart. In such an embodiment, the vehicle adaptive hybrid braking program can be downloaded and installed from a network through a communication device, or installed from a storage device 1003, or installed from a ROM 1002. When the vehicle adaptive hybrid braking program is executed by the processing device 1001, the above functions defined in the method of the embodiment disclosed in the present application are executed.

[0154] The vehicle provided by the present application adopts the vehicle adaptive hybrid braking method in the above embodiment, which can solve the technical problem of how to ensure the braking safety of the vehicle. Compared with the prior art, the beneficial effects of the vehicle provided by the present application are the same as the beneficial effects of the vehicle adaptive hybrid braking method provided by the above embodiment, and other technical features in the vehicle are the same as the features disclosed in the method of the previous embodiment, which will not be repeated here.

[0155] It should be understood that the various parts disclosed in this application can be implemented by hardware, software, firmware or a combination thereof. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0156] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0157] The present application provides a storage medium having computer-readable program instructions (ie, a vehicle adaptive hybrid braking program) stored thereon, wherein the computer-readable program instructions are used to execute the vehicle adaptive hybrid braking method in the above-mentioned embodiment.

[0158] The storage medium provided in the present application may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, systems or devices, or any combination of the above. More specific examples of storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM: RandomAccess Memory), a read-only memory (ROM: Read Only Memory), an erasable programmable read-only memory (EPROM: Erasable Programmable Read Only Memory or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM: CD-Read Only Memory), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, system or device. The program code contained on the storage medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency: Radio Frequency), etc., or any suitable combination of the above.

[0159] The above storage medium may be included in the vehicle; or may exist independently without being installed in the vehicle.

[0160] The storage medium carries one or more programs, and when the one or more programs are executed by the vehicle, the vehicle can effectively perform adaptive hybrid braking.

[0161] The vehicle adaptive hybrid braking program code for performing the operations of the present application may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0162] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and vehicle adaptive hybrid braking program products according to various embodiments of the present application. In this regard, each box in the flowchart or block diagram may represent a module, a program segment or a portion of a code, which contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the boxes may also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, as well as the combination of boxes in the block diagram and / or flowchart, can be implemented with a dedicated hardware-based system that performs the specified functions or operations, or can be implemented with a combination of dedicated hardware and computer instructions.

[0163] The modules involved in the embodiments of the present application may be implemented by software or hardware, wherein the name of the module does not limit the unit itself in some cases.

[0164] The readable storage medium provided by the present application is a storage medium, which stores computer-readable program instructions (i.e., vehicle adaptive hybrid braking program) for executing the above-mentioned vehicle adaptive hybrid braking method, and can solve the technical problem of how to ensure the safety of vehicle braking. Compared with the prior art, the beneficial effects of the storage medium provided by the present application are the same as the beneficial effects of the vehicle adaptive hybrid braking method provided by the above-mentioned embodiment, and will not be repeated here.

[0165] The above are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A vehicle adaptive hybrid braking method, characterized in that: The method comprises: Determine the required deceleration according to the target speed information and the preset distance information between the vehicle and the preceding vehicle; Performing a real-time numerical comparison between the preset braking deceleration and the required deceleration; The hydraulic retarder, wheel brakes and engine are controlled to brake the vehicle based on the deceleration comparison result.

2. The vehicle adaptive hybrid braking method according to claim 1, characterized in that: Before comparing the preset braking deceleration with the required deceleration in real time, the method further includes: Performing Kalman filter calculation according to the target speed information to obtain the real-time slope of the vehicle; The preset braking acceleration is determined based on the real-time slope of the vehicle.

3. The vehicle adaptive hybrid braking method according to claim 2, characterized in that: The preset braking deceleration includes the maximum braking deceleration of the engine; The step of controlling the hydraulic retarder, the wheel brake and the engine to brake the vehicle based on the deceleration comparison result comprises: When the required deceleration is less than the maximum engine braking deceleration, the engine is controlled to perform vehicle compound braking.

4. The vehicle adaptive hybrid braking method according to claim 3, characterized in that: The preset braking deceleration also includes the maximum braking deceleration of the retarder; The step of controlling the hydraulic retarder, the wheel brake and the engine to brake the vehicle based on the deceleration comparison result also includes: When the required deceleration is between the maximum braking deceleration of the engine and the maximum braking deceleration of the retarder, and the current retarder torque percentage is less than a preset torque threshold, the wheel brakes are controlled to perform vehicle feedforward braking based on the required deceleration; When the required deceleration is between the maximum braking deceleration of the engine and the maximum braking deceleration of the retarder, and the current retarder torque percentage is greater than a preset torque threshold, the hydraulic retarder is controlled to perform vehicle feedforward braking.

5. The vehicle adaptive hybrid braking method according to claim 4, characterized in that: The step of controlling the hydraulic retarder, the wheel brake and the engine to brake the vehicle based on the deceleration comparison result also includes: When the required deceleration is greater than the maximum braking deceleration of the retarder and the current retarder torque percentage is greater than a preset torque threshold, the wheel brakes are controlled to perform vehicle feedforward braking based on the required deceleration, and the hydraulic retarder is controlled to perform vehicle feedforward braking.

6. The vehicle adaptive hybrid braking method according to claim 3, characterized in that: The step of controlling the engine to perform vehicle compound braking comprises: Determining the engine feedforward torque according to the real-time slope of the vehicle and the required deceleration; determining an engine feedback torque based on the target speed information; The composite braking torque corresponding to the engine is determined according to the engine feedforward torque and the engine feedback torque, and the engine is controlled by the composite braking torque to brake the vehicle.

7. The vehicle adaptive hybrid braking method according to claim 4, characterized in that: The step of controlling the hydraulic retarder to perform vehicle feedforward braking comprises: determining a retarder feedforward torque according to the required deceleration; The vehicle brakes by controlling the hydraulic retarder via retarder feed-forward torque.

8. A vehicle adaptive hybrid braking device, characterized in that: The device comprises: A deceleration determination module, used to determine a required deceleration according to target speed information and preset distance information between the vehicle and the preceding vehicle; A braking comparison module, used for performing a real-time numerical comparison between a preset braking deceleration and the required deceleration; The brake control module is used to control the hydraulic retarder, wheel brakes and engine to brake the vehicle based on the deceleration comparison result.

9. A vehicle, characterized in that: The vehicle includes: a hydraulic retarder, wheel brakes, an engine, a memory, a processor, and a vehicle adaptive hybrid braking program stored in the memory and executable on the processor, wherein the vehicle adaptive hybrid braking program is configured to implement the steps of the vehicle adaptive hybrid braking method as described in any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium stores a vehicle adaptive hybrid braking program, and when the vehicle adaptive hybrid braking program is executed by the processor, the steps of the vehicle adaptive hybrid braking method according to any one of claims 1 to 7 are implemented.

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