CN119459620A - Redundant vehicle dynamic control method, controller and electronic hydraulic brake system - Google Patents
Redundant vehicle dynamic control method, controller and electronic hydraulic brake system Download PDFInfo
- Publication number
- CN119459620A CN119459620A CN202510065779.3A CN202510065779A CN119459620A CN 119459620 A CN119459620 A CN 119459620A CN 202510065779 A CN202510065779 A CN 202510065779A CN 119459620 A CN119459620 A CN 119459620A
- Authority
- CN
- China
- Prior art keywords
- braking force
- vehicle
- wheel
- vdc system
- steering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 50
- 230000004913 activation Effects 0.000 claims abstract description 20
- 230000001133 acceleration Effects 0.000 claims abstract description 11
- 239000012530 fluid Substances 0.000 claims description 56
- 230000004044 response Effects 0.000 claims description 23
- 238000006073 displacement reaction Methods 0.000 claims description 20
- 238000004590 computer program Methods 0.000 claims description 5
- 238000004422 calculation algorithm Methods 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims description 3
- 230000001276 controlling effect Effects 0.000 abstract description 21
- 230000008569 process Effects 0.000 abstract description 10
- 230000001105 regulatory effect Effects 0.000 abstract description 10
- 230000008859 change Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 9
- 230000006870 function Effects 0.000 description 6
- 238000004891 communication Methods 0.000 description 4
- 230000001965 increasing effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 229910018904 PSV1 Inorganic materials 0.000 description 2
- 229910018888 PSV2 Inorganic materials 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 230000006399 behavior Effects 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 238000011217 control strategy Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000005856 abnormality Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 230000006837 decompression Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 230000001502 supplementing effect Effects 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Landscapes
- Regulating Braking Force (AREA)
Abstract
The application provides a redundant vehicle dynamic control method, a controller and an electronic hydraulic brake system, wherein the method comprises the steps that an ECU control module monitors dynamic parameters of a vehicle in a running state in real time, wherein the dynamic parameters comprise steering angle, vehicle speed, yaw rate and lateral acceleration of the vehicle; and when the activation condition is met, the ECU control module determines the braking force required by the target wheel controlled by the VDC system based on the steering working condition of the vehicle, and further adjusts the braking of the target wheel through the VDC system, wherein the steering working condition comprises oversteer and understeer. The application provides an effective solution for two working conditions of oversteering and understeering, and in the dynamic control process of the vehicle, the braking force of the wheels is regulated in a real-time closed loop manner by accurately controlling the braking force of the wheels. Therefore, the system can quickly respond to the dynamic change of the vehicle, adjust the braking force in time and ensure the stability of the vehicle in the running process.
Description
Technical Field
The application relates to the technical field of brake-by-wire, in particular to a redundant vehicle dynamic control method, a controller and an electronic hydraulic brake system.
Background
The dynamic vehicle Control system (VEHICLE DYNAMICS Control, VDC) is an advanced vehicle safety technology, and has the core function of monitoring and adjusting the braking, steering and power output of the vehicle in real time by identifying the running state of the vehicle, so as to provide stability and controllability support for the driver.
This function of the VDC system is mainly performed by the electronic stability program control system (Electronic stability Control, ESC). The ESC system can judge the dynamic state of the vehicle through a complex algorithm and accurate sensor data, and actively boost the braking system of the vehicle when necessary, so as to adjust the running track of the vehicle.
When the vehicle is in dynamic control of the vehicle, if the vehicle is in an understeer or oversteer condition, it is necessary to immediately make a braking adjustment to the vehicle to correct the understeer or oversteer. The vehicle yaw is increased by additionally braking the rear wheels on the inner side of the vehicle, so that the vehicle head swings towards the inward bending direction, and the vehicle yaw control method is an effective dynamic control strategy. However, during dynamic control of the vehicle, if the build-up pressure response of the ESC system is slow, meaning that it takes longer to build up the braking pressure, this may lead to a delay in braking effect, failing to correct the driving trajectory of the vehicle in time, thus possibly increasing the risk of the vehicle running out of control. Meanwhile, the control accuracy is not high when the ESC is used for active pressurization, so that fluctuation of a braking effect can be caused, and the dynamic performance of a vehicle is affected.
Disclosure of Invention
Aiming at the defects in the prior art, the application provides a redundant vehicle dynamic control method, a controller and an electronic hydraulic brake system, which aim to solve the problems in the prior art.
In order to achieve the above objects and other advantages, the present invention is implemented by the following technical solutions:
in a first aspect, the present application provides a redundant vehicle dynamic control method, including:
the ECU control module monitors dynamic parameters of the vehicle in real time under the running state, wherein the dynamic parameters comprise steering angle, vehicle speed, yaw rate and lateral acceleration of the vehicle;
Analyzing the dynamic parameters and judging whether the activation condition of the VDC system is met;
and when the activation condition is met, the ECU control module determines the braking force required by the target wheel controlled by the VDC system based on the steering working condition of the vehicle, and further adjusts the braking of the target wheel through the VDC system, wherein the steering working condition comprises oversteer and understeer.
According to the redundant vehicle dynamic control method provided by the application, the steering working condition is an oversteer working condition and no brake pedal displacement signal is detected;
And when the activation condition is met, the ECU control module determines braking force required by the target wheel controlled by the VDC system based on the steering working condition of the vehicle, and further adjusts the braking of the target wheel through the VDC system, and the method comprises the following steps:
In response to a steering condition of oversteer, selecting at least one outside wheel far from a steering center as a target wheel for applying braking force when no large slip of the vehicle is detected;
Calculating a first yaw moment which is required for correcting oversteer and is opposite to the yaw speed of the vehicle according to the dynamic parameters;
calculating a braking force applied to a target wheel according to the first yaw moment and the adhesion relationship between the tire and the ground;
the ECU control module transmits the calculated braking force to the VDC system, which applies a corresponding braking force to the target wheel.
According to the redundant vehicle dynamic control method provided by the application, the steering working condition is an oversteer working condition and a brake pedal displacement signal is detected;
And when the activation condition is met, the ECU control module determines braking force required by the target wheel controlled by the VDC system based on the steering working condition of the vehicle, and further adjusts the braking of the target wheel through the VDC system, and the method comprises the following steps:
in response to a steering condition of oversteer, selecting, when a slip ratio of the vehicle is not detected, an outer front wheel far from the steering center and a contralateral rear wheel near the steering center as target wheels for applying and releasing braking forces, respectively;
calculating a second yaw moment which is required for correcting oversteer and is opposite to the yaw speed of the vehicle according to the dynamic parameters;
according to the two yaw moments and the adhesive force relation between the tires and the ground, respectively calculating a first braking force applied to the outer front wheels and a second braking force required to be released by the opposite side rear wheels;
the ECU control module transmits the calculated braking force to the VDC system, which releases the second braking force to the opposite side rear wheels while applying the first braking force to the outer side front wheels.
According to the redundant vehicle dynamic control method provided by the application, the steering working condition is an understeer working condition, and a brake pedal displacement signal is not detected;
And when the activation condition is met, the ECU control module determines braking force required by the target wheel controlled by the VDC system based on the steering working condition of the vehicle, and further adjusts the braking of the target wheel through the VDC system, and the method comprises the following steps:
in response to a steering condition of understeer, selecting at least one inner wheel near a steering center as a target wheel for applying braking force when no large slip of the vehicle is detected;
Calculating a third yaw moment which is required for correcting understeer and has the same direction as the yaw speed of the vehicle according to the dynamic parameters;
Calculating a braking force applied to the target wheel according to the third yaw moment and the adhesion relationship between the tire and the ground;
the ECU control module transmits the calculated braking force to the VDC system, which applies a corresponding braking force to the target wheel.
According to the redundant vehicle dynamic control method provided by the application, the steering working condition is an understeer working condition and a brake pedal displacement signal is detected;
And when the activation condition is met, the ECU control module determines braking force required by the target wheel controlled by the VDC system based on the steering working condition of the vehicle, and further adjusts the braking of the target wheel through the VDC system, and the method comprises the following steps:
In response to a steering condition of oversteer, selecting, when a slip ratio of the vehicle is not detected, an inner rear wheel close to the steering center and an opposite front wheel far from the steering center as target wheels for applying and releasing braking forces, respectively;
Calculating a fourth yaw moment which is required for correcting oversteer and is in the same direction as the yaw speed of the vehicle according to the dynamic parameters;
According to the four yaw moments and the adhesive force relation between the tires and the ground, respectively calculating a third braking force applied to the inner rear wheels and a fourth braking force required to be released by the opposite side front wheels;
the ECU control module transmits the calculated braking force to the VDC system, which releases the fourth braking force to the pair of side front wheels while applying the third braking force to the inner rear wheels.
According to the method for dynamically controlling the redundant vehicle provided by the application, the step of adjusting the braking of the target wheel through the VDC system comprises the following steps:
when the VDC system is activated, the VDC system establishes a braking force applied to a target wheel end;
According to a first control instruction issued by the VDC system, starting to build pressure by a pressure building module of the electro-hydraulic brake, powering on a PSV electromagnetic valve and an RV electromagnetic valve after building the pressure, opening a booster valve of a corresponding wheel end of braking force to be regulated by an ESC module, closing booster valves of other wheel ends, and regulating and controlling the braking force by brake fluid from the opened booster valve;
In the dynamic control of the VDC system, when the braking force of the wheel end needs to be reduced, the VDC system establishes the braking force for releasing the target wheel end, opens the corresponding pressure release valve of the wheel end to release pressure, and releases the braking fluid into the accumulator of the ESC module.
According to the method for dynamically controlling a redundant vehicle provided by the application, after the step of discharging brake fluid into an accumulator of an ESC module, the method comprises the following steps:
judging whether the brake fluid in the accumulator exceeds a set brake fluid threshold value;
And responding to the brake fluid in the energy accumulator exceeding the brake fluid threshold, controlling the motor of the ESC module to work according to a second control instruction issued by the VDC system, closing the SV electromagnetic valve, pumping the brake fluid out of the energy accumulator by the plunger pump, and returning the brake fluid into the pressure build-up cavity through the RV electromagnetic valve and the PSV electromagnetic valve, wherein the brake fluid pushes back the piston in the pressure build-up cavity until the hydraulic pressure of the ESC module is the same as the hydraulic pressure in the pressure build-up cavity.
According to the method for dynamically controlling the redundant vehicle, in the dynamic control of the VDC system, when the braking force of the wheel end needs to be reduced, a pressure release valve corresponding to the wheel end is opened to release pressure, and the method further comprises the following steps:
judging whether the braking force applied to the target wheel end is larger than a set braking force threshold value or not;
And responding to the fact that the braking force applied to the target wheel end is larger than a set braking force threshold value, opening a pressure release valve to release pressure according to a third control instruction issued by the VDC system, and simultaneously controlling a plunger pump of the ESC module to cooperate with the pressure release valve to release pressure to directly reflux brake fluid of the wheel end into the pressure build cavity.
In a second aspect, the present application provides a controller comprising a processor and a memory, the memory storing a computer program executable by the processor, the processor being executable to implement the redundant vehicle dynamic control method of the first aspect.
In a third aspect, the present application provides an electro-hydraulic brake system comprising a controller as described in the first aspect.
The application provides a redundant vehicle dynamic control method, a controller and an electronic hydraulic brake system, wherein the method comprises the steps that an ECU control module monitors dynamic parameters of a vehicle in a running state in real time, wherein the dynamic parameters comprise steering angle, speed, yaw rate and lateral acceleration of the vehicle; and when the activation condition is met, the ECU control module determines the braking force required by the target wheel controlled by the VDC system based on the steering working condition of the vehicle, and further adjusts the braking of the target wheel through the VDC system, wherein the steering working condition comprises oversteer and understeer. The application provides an effective solution for two working conditions of oversteering and understeering, and in the dynamic control process of the vehicle, the braking force of the wheels is regulated in a real-time closed loop manner by accurately controlling the braking force of the wheels. The system can respond to dynamic changes of the vehicle rapidly, adjust braking force in time, ensure stability of the vehicle in the running process, and accurately control application and release of the braking force through real-time closed-loop adjustment, so that unnecessary braking operation is avoided to cause abrasion and damage to a braking system.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other embodiments may be obtained according to these drawings without inventive effort to a person skilled in the art.
FIG. 1 is a flow chart of a redundant vehicle dynamic control method provided by an embodiment of the present application;
FIG. 2 is a logic diagram of single wheel active boost control of a brake-by-wire system provided by an embodiment of the present application;
FIG. 3 is a logic diagram of a two-wheel active boost control of a brake-by-wire system provided by an embodiment of the present application;
Fig. 4 is a schematic structural diagram of a controller according to an embodiment of the present invention.
Detailed Description
The foregoing description is only an overview of the present application, and is intended to be implemented in accordance with the teachings of the present application, as well as the preferred embodiments thereof, together with the following detailed description of the application, given by way of illustration only, together with the accompanying drawings.
It should be noted that those skilled in the art explicitly and implicitly understand that the described embodiments of the application can be combined with other embodiments without conflict. Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The terms "a," "an," "the," and similar referents in the context of the application are not to be construed as limiting the quantity, but rather as singular or plural. The terms "comprising," "including," "having," and any variations thereof, are intended to cover a non-exclusive inclusion, and the terms "first," "second," "third," etc. as used herein, are merely distinguishing between similar objects and not representing a particular ordering of objects.
The electronic control module (Electronic Control Unit, ECU) is used for realizing the accurate control and management of each electronic system of the automobile by means of receiving sensor data, processing information, sending instructions and the like, and ensuring the safe and reliable operation of the automobile. Referring to fig. 1, an embodiment of the present application provides a redundant vehicle dynamic control method, including:
Step S1, an ECU control module monitors dynamic parameters in real time under the running state of the vehicle, wherein the dynamic parameters comprise steering angle, vehicle speed, yaw rate and lateral acceleration of the vehicle.
And S2, analyzing the dynamic parameters and judging whether the activation condition of the VDC system is met.
Specifically, the sensors monitor dynamic parameters of the vehicle in real time. If the steering angle sensor is arranged on the steering system, the rotation angle of the steering wheel is monitored in real time. The vehicle speed sensor is typically mounted on a gearbox or wheels, calculates the vehicle speed by measuring the rotational speed of the wheels, and transmits a vehicle speed signal to the ECU control module. The yaw rate and the lateral acceleration may be measured by an inertial measurement unit (Inertial Measurement Unit, IMU) or by dedicated yaw rate and lateral acceleration sensors. And the ECU control module calculates and analyzes the received dynamic parameter signals in real time according to a preset algorithm and model, and judges the running state of the vehicle.
The activation condition of the VDC system is generally based on the determination of the vehicle running state by the ECU, and when it is detected that the vehicle is in an unstable or dangerous state, such as the presence of yaw rate abnormality (detection of yaw rate exceeding a normal range may mean that the vehicle is oversteering or understeering), excessive lateral acceleration (detection of lateral acceleration exceeding a preset threshold value may mean that the vehicle is sideslip or out of control), wheel slip (determination of whether the wheels slip by comprehensive analysis of a plurality of sensor data), etc., the vehicle dynamic control system automatically intervenes to maintain the stability and safety of the vehicle.
And step S3, when the activation condition is met, the ECU control module determines the braking force required by the target wheel controlled by the VDC system based on the steering working condition of the vehicle, and further adjusts the braking of the target wheel through the VDC system, wherein the steering working condition comprises oversteer and understeer.
In this embodiment, the steering condition is an oversteer condition and no brake pedal displacement signal is detected, and step S3 specifically includes:
Step SA301, in response to the oversteering steering condition, selecting at least one outer wheel far from the steering center as a target wheel for applying braking force when no large slip of the vehicle is detected;
Step SA302, calculating a first yaw moment which is required for correcting oversteer and is opposite to the yaw speed of the vehicle according to the dynamic parameters;
Step SA303, calculating braking force applied to the target wheel according to the first yaw moment and the adhesion relationship between the tire and the ground;
in step SA304, the ECU control module sends the calculated braking force to the VDC system, and the VDC system applies corresponding braking force to the target wheel.
Specifically, when the system determines that the vehicle is trending for oversteering, the VDC system may immediately intervene in the start response. The VDC system simultaneously evaluates the slip state between the tire and the ground, and the situation that the vehicle is in large slip is not detected, namely, the system judges that the slip rate between the tire and the ground is lower, and the degree of large slip is not reached. Since the dynamic behavior of the vehicle is still in a controllable range, no brake pedal displacement signal is detected (i.e. the pedal displacement sensor does not detect the amount of displacement of the brake pedal), which means that the driving trajectory of the vehicle is slightly changed, such as a slight curve or avoidance of an obstacle, but such a change is not sufficient to cause a runaway of the vehicle or require an emergency braking of the driver. At this time, the system selects at least one of the outer wheels that is far from the steering center as a target wheel for applying braking force. This is because in the case of oversteer, applying a braking force to the outer wheels can create an inward yaw moment that helps correct the tendency of oversteer. The application of such braking force is precise and transient and is intended to quickly correct the steering state of the vehicle, rather than to reduce the speed of the vehicle or stop the vehicle. To dynamically balance the outward yaw moment generated by oversteer during vehicle travel.
The ECU control module determines a direction in which the oversteer needs to be corrected, i.e., a direction opposite to the current yaw rate of the vehicle, based on the steering angle and the yaw rate of the vehicle. Based on the vehicle's mass, centroid position, vehicle speed, etc., as well as the desired correction direction and degree, the ECU control module calculates a first yaw moment required to correct the oversteer. Based on the first yaw moment and the adhesion relationship between the tire and the ground, the ECU calculates a braking force that needs to be applied to the target wheel. This braking force must be large enough to generate the first yaw moment required, but not exceed the adhesion limit between the tire and the ground, otherwise resulting in wheel slip.
The ECU control module sends the calculated braking force signal to the VDC system, the VDC system generates a corresponding control command, the ESC module executes the corresponding control command, and corresponding braking force is applied to the target wheels (two outer wheels, namely an outer front wheel and an outer rear wheel) through an actuator (such as a solenoid valve and the like) of a control brake actuating mechanism. This braking force will create a yaw moment in the opposite direction to the vehicle yaw rate and help correct the oversteer. For this oversteer condition and without the need for driver emergency braking, the yaw moment of the vehicle is balanced by way of VDC system braking for the two outside wheels being steered to ensure the comfort of stable steering of the vehicle.
When there is a slight oversteering tendency, i.e. low vehicle speed and good road adhesion, the yaw moment of the vehicle can also be adjusted by braking one of the outer wheels, typically the outer front wheel.
In this embodiment, the steering condition is an oversteer condition and a brake pedal displacement signal is detected, and step S3 specifically includes:
Step SB301, in response to the oversteer steering condition, when the slip ratio of the vehicle is not detected, selecting the outer front wheel far from the steering center and the opposite rear wheel near the steering center as target wheels for applying and releasing braking force, respectively;
step SB302, calculating a second yaw moment which is required for correcting oversteer and is opposite to the yaw speed of the vehicle according to the dynamic parameters;
Step SB303, respectively calculating a first braking force applied to the outer front wheels and a second braking force required to be released by the opposite side rear wheels according to the two yaw moments and the adhesion relationship between the tires and the ground;
In step SB304, the ECU control module transmits the calculated braking force to the VDC system, which applies a first braking force to the outboard front wheels while releasing a second braking force to the inboard rear wheels.
Specifically, when the system determines that the vehicle is trending for oversteering, the VDC system may immediately intervene in the start response. The driver is aware that the vehicle is oversteering and begins to depress the brake pedal, and the vehicle's brake system begins to operate, attempting to reduce the vehicle speed by reducing the wheel speed. The system first determines whether the vehicle is experiencing slip (i.e., the degree of slip of the wheels relative to the ground). If no slip ratio of the vehicle is detected, it is indicated that the friction between the wheels and the ground is still sufficient, and the vehicle has not entered a serious runaway condition. At this time, the system selects as target wheels the outer front wheel far from the steering center and the opposite rear wheel near the steering center. The outer front wheels are used for applying braking force to help reduce steering angle, and the opposite side rear wheels release braking force to help the vehicle to resume normal running track.
The ECU control module calculates a yaw moment required to correct the oversteer based on the dynamic parameters of the vehicle. In the calculation process, the adhesion relationship between the tire and the ground is also considered, so that the braking force is ensured not to exceed the ground grabbing capability of the tire, and the wheel slip is avoided. The VDC system then pressurizes the first braking force applied to the outside front wheels by controlling the actuator of the brake actuator while releasing the second braking force released to the side rear wheels to ensure the steering ability of the vehicle. The application and release of the wheel end braking force needs to be quick and accurate to ensure that the vehicle can resume stable in time.
When the driver realizes that the vehicle is oversteered and begins to depress the brake pedal, simply relying on braking may not be able to control the travel path of the vehicle quickly and effectively. The VDC system will then intelligently adjust the brake force distribution of each wheel based on the evaluation. By precisely controlling the distribution of the braking force, additional braking force is applied to the outer front wheels to help reduce the steering angle while releasing or reducing the braking force to the opposite rear wheels to assist the vehicle in returning to a normal running track. Therefore, the VDC system can rapidly intervene and correct oversteer in the case where the driver may not respond timely or accurately, ensure a stable steering ability of the vehicle while maintaining a stable driving state, thereby enhancing driving safety.
In this embodiment, the steering condition is an understeer condition and no brake pedal displacement signal is detected, and step S3 specifically includes:
Step SC301, in response to the understeer steering condition, selecting at least one inner wheel close to the steering center as a target wheel for applying braking force when no large slip of the vehicle is detected;
Step SC302, calculating a third yaw moment which is required for correcting understeer and has the same direction with the yaw speed of the vehicle according to the dynamic parameters;
step SC303, calculating the braking force applied to the target wheel according to the third yaw moment and the adhesion relationship between the tire and the ground;
In step SC304, the ECU control module transmits the calculated braking force to the VDC system, and the VDC system applies a corresponding braking force to the target wheel.
Specifically, when the system determines that the vehicle is trending for understeer, the VDC system may immediately intervene to begin responding. In response to an understeer steering condition and no brake pedal displacement signal detected, the dynamic behavior of the vehicle is indicated to be within a controllable range. In the case that no large slip of the vehicle is detected, the system selects at least one inner wheel close to the steering center as a target wheel for applying braking force according to a preset algorithm. By applying a braking force to the rear wheels on the inside, a yaw moment in the same direction as the yaw velocity of the vehicle can be generated, helping the vehicle to resume its normal steering trajectory. The system calculates a braking force applied to the target wheel based on the third yaw moment and the adhesion relationship between the tire and the ground. The adhesion relationship is typically obtained through tire models or experimental data describing the adhesion between the tire and the ground at various vehicle speeds, tire pressures, and road conditions. Ensuring that the applied braking force does not exceed the adhesion limit between the tyre and the ground, avoiding wheel locking or slipping. The ECU control module sends the calculated braking force to the VDC system, and the VDC system applies corresponding braking force to the target wheel after receiving the instruction.
The ECU control module sends the calculated braking force signal to the VDC system, the VDC system generates a corresponding control command, the ESC module executes the corresponding control command, and applies a corresponding braking force to the target wheel (two inner wheels, i.e., the inner front wheel and the inner rear wheel) by controlling an actuator (e.g., a solenoid valve, etc.) of the brake actuator. This braking force will create a yaw moment in the same direction as the vehicle yaw rate, helping to correct the understeer. For the understeer condition and the situation that the driver is not required to brake urgently, the yaw moment of the vehicle is balanced by braking the VDC system for the two inner wheels to be steered, so that the comfort of stable steering of the vehicle is ensured.
When there is a slight understeer tendency, i.e. a low vehicle speed and good road adhesion, the yaw moment of the vehicle can also be adjusted by braking one of the inner wheels, typically the inner rear wheel.
In this embodiment, the steering condition is an understeer condition and a brake pedal displacement signal is detected, and step S3 specifically includes:
Step SD301, in response to the oversteering steering condition, when the slip rate of the vehicle is not detected, selecting the inner rear wheel close to the steering center and the opposite front wheel far from the steering center as target wheels for applying and releasing braking force respectively;
Step SD302, calculating a fourth yaw moment which is required for correcting oversteer and is opposite to the yaw speed of the vehicle according to the dynamic parameters;
step SD303, respectively calculating a third braking force applied to the inner rear wheels and a fourth braking force required to be released by the opposite side front wheels according to the four yaw moments and the adhesion relationship between the tires and the ground;
in step SD304, the ECU control module sends the calculated braking force to the VDC system, which applies a third braking force to the inboard rear wheels while releasing a fourth braking force to the inboard front wheels.
Specifically, the VDC system may immediately intervene to begin responding upon detecting that the vehicle is under-turned and that the brake pedal has a displacement signal. If the system does not detect the slip rate of the vehicle, it indicates that the friction between the wheels and the ground is still sufficient and the vehicle has not entered a serious runaway condition. The dynamic state of the vehicle is analyzed, the inside rear wheel close to the steering center is selected as the wheel applying the additional braking force, and the opposite side front wheel far from the steering center is selected as the wheel needing to release the braking force. Based on the steering dynamics principle of the vehicle, increasing the braking force of the inner rear wheels can help the vehicle to rotate more closely around the steering center, while decreasing the braking force of the opposite front wheels helps to reduce the steering resistance of the wheels and promote the vehicle to rotate in the desired direction. The steering response of the vehicle is adjusted by differential braking, correcting the understeer tendency.
The system calculates a fourth yaw moment in the same direction as the current yaw rate of the vehicle, which is required to correct the understeer according to the dynamic parameters of the vehicle. This moment is to help the vehicle reach the desired steering trajectory faster. In the calculation process, in combination with the adhesion relationship between the tire and the ground, the system calculates a third braking force to be applied to the inside rear wheel and a fourth braking force to be released from the opposite side front wheel, respectively. The VDC system pressurizes the third braking force applied to the inner rear wheel by controlling an actuator of the brake actuator, and simultaneously depressurizes the fourth braking force released from the opposite front wheel to ensure steering ability of the vehicle. The application and release of the wheel end braking force needs to be quick and accurate to ensure that the vehicle can resume stable in time.
Therefore, particularly when emergency obstacle avoidance or high-speed turning is required, the running track of the vehicle cannot be quickly and effectively controlled by simply relying on braking, at the moment, the VDC is quickly involved, the understeer of the vehicle is quickly corrected by accurately controlling the braking force of a specific wheel, and the running stability and safety of the vehicle are improved.
In this embodiment, in step S3, the step of adjusting the braking of the target wheel by the VDC system includes:
When the VDC system is activated, the VDC system establishes a braking force applied to the target wheel end;
According to a first control instruction issued by the VDC system, starting to build pressure by a pressure building module of the electro-hydraulic brake, powering on a PSV electromagnetic valve and an RV electromagnetic valve after building the pressure, opening a booster valve of a corresponding wheel end of braking force to be regulated by the ESC module, closing booster valves of other wheel ends, and regulating the braking force by brake fluid entering the wheel end from the opened booster valve;
In dynamic control of the VDC system, when braking force of the wheel end needs to be reduced, the VDC system establishes braking force of the target wheel end to be released, a pressure release valve corresponding to the wheel end is opened for pressure release, and brake fluid is released into an energy accumulator of the ESC module.
Specifically, when the brake-by-wire braking module does not build pressure during braking, the electromagnetic valve in the brake-by-wire system is in an initial state, as shown in fig. 2, and is a hydraulic control schematic diagram of the Twobox brake-by-wire system, and the frame Fang Xuxian in the drawing comprises components such as an oilcan, a master cylinder, an electric cylinder, a displacement sensor, a CSV electromagnetic valve, a PSV electromagnetic valve, a pressure sensor and the like. These components together form the main control module of the hydraulic system, responsible for the establishment and control of the hydraulic pressure. The lower dashed box contains a plurality of solenoid valves, ESC motors, plunger pumps, accumulators, pressure sensors, etc. This part is mainly a hydraulic execution module for effecting the distribution of hydraulic pressure and executing specific braking actions. The CSV1 and CSV2 electromagnetic valves are responsible for switching on and off of a braking loop from a master cylinder to a wheel cylinder, and electrifying is closed. The SSV solenoid valve is used for switching on and switching off a standby passage of the mechanical backup, and is electrified to be opened. The PSV1 and PSV2 electromagnetic valves are responsible for switching on and off a brake loop from an electric cylinder to a wheel cylinder, and are electrified and opened. The RV1 and RV2 electromagnetic valves are pressure regulating valves and are responsible for regulating the hydraulic pressure in a braking system loop and switching off and opening. The SV1 and SV2 solenoid valves are fluid-filling valves, and are responsible for filling brake fluid into the brake system from the oilcan and closing the brake system after power failure. IV1F, IV1R, IV and F, IV R are respectively four wheel-end pressure-increasing valves, are responsible for controlling the oil inlet passage of each wheel-end brake and are opened in a power-off mode, and OV1F, OV1R, OV and F, OV R are respectively four wheel-end pressure-releasing valves, are responsible for controlling the oil outlet passage of each wheel-end brake and are closed in a power-off mode.
The VDC system is activated for intervention in response to a steering condition oversteering to the left and no brake pedal displacement signal is detected. And according to the determined target wheel is the right front wheel and the calculated braking force required to be applied, the building module starts to work according to a first control instruction issued by the VDC system, and the required hydraulic pressure is provided for the braking system. The PSV solenoid valve and RV solenoid valve are energized open allowing high pressure brake fluid to enter the brake system. As shown in fig. 2, the IV1R solenoid remains de-energized open, the IV1F, IV2F, IV R solenoid is energized closed, and each of the OV1F, OV1R, OV2F, OV R solenoids remains de-energized closed. Since only the booster valve of the front wheel on the right side is opened for boosting, the booster valves of the other wheel ends are closed at the same time. With the inflow of brake fluid, the brake of the front right wheel starts to operate, and a moment opposite to oversteer of the vehicle is generated to help the vehicle to stabilize. The VDC system ensures that the vehicle can stably run according to the intention of the driver by continuously monitoring dynamic parameters of the vehicle and adjusting braking force applied to the right front wheel in real time. In the dynamic process of the vehicle, the VDC system precisely controls the opening and closing states of all electromagnetic valves, and the braking force is precisely regulated and controlled to each wheel, so that the precise control of the dynamic performance of the vehicle is realized. If the target wheels are the right front wheel and the right rear wheel under the working condition, as shown in fig. 3, the IV1R, IV R solenoid valve needs to be kept in a power-off open state, and the IV1F, IV F solenoid valve is powered on and closed. At the moment, the VDC system regulates and controls the braking force of the two outer wheels in real time, and the accurate control of the VDC system is met.
The VDC system is activated for intervention in response to a steering condition oversteering to the left and a brake pedal displacement signal is detected. According to the determined target wheels are the right front wheel and the left rear wheel and the calculated first braking force required to be applied to the right front wheel and the calculated second braking force required to be released by the left rear wheel, at the moment, the IV1R electromagnetic valve is kept in a power-off open state, the IV1F, IV2F, IV R electromagnetic valve is powered on and closed, and the right front wheel is boosted through the opened booster valve. The OV2R solenoid valves are electrified and opened, each solenoid valve of the OV1F, OV1R, OV F solenoid valve is kept in a power-off closing state, and the left rear wheel is decompressed through the opened decompression valve. With the inflow of the brake fluid, the brake of the front right wheel starts to operate, a moment opposite to oversteer of the vehicle is generated, and simultaneously, the wheel end braking force of the rear left wheel is decompressed, so that the brake fluid is discharged into the accumulator A2. In the dynamic control process of the vehicle, the real-time closed-loop adjustment of the braking force is realized, and the purposes of rapidly intervening and timely correcting oversteering are achieved.
In this embodiment, after the step of discharging the brake fluid into the accumulator of the ESC module, comprising:
Judging whether the brake fluid in the accumulator exceeds a set brake fluid threshold value;
And responding to the brake fluid in the energy accumulator exceeding a brake fluid threshold, and controlling the motor of the ESC module to work according to a second control instruction issued by the VDC system, wherein the SV electromagnetic valve is electrified and closed, the plunger pump pumps the brake fluid out of the energy accumulator, and the brake fluid flows back into the pressure build-up cavity through the RV electromagnetic valve and the PSV electromagnetic valve, and the brake fluid pushes back the piston in the pressure build-up cavity until the hydraulic pressure of the ESC module is the same as the hydraulic pressure in the pressure build-up cavity.
Specifically, in a hydraulic brake system, accumulators (A1, A2) are used to store brake fluid and to release wheel end braking forces when necessary, returning the brake fluid to a main control module of the hydraulic system. When the vehicle is in the VDC condition for a long time, brake fluid is frequently supplied to the wheel end to provide necessary braking force, and at the same time, the braking force of the wheel end is frequently fed back and enters the accumulator. So that the accumulator is filled, resulting in a wheel end brake fluid that cannot be discharged. In order to set the brake fluid quantity in the accumulator, a pressure sensor or a fluid level sensor is provided in the accumulator to monitor whether the brake fluid in the accumulator exceeds a set brake fluid threshold value. When the amount of brake fluid in the accumulator exceeds a set brake fluid threshold, the VDC system controls operation of the ESC motor M2. For the energy accumulator A1, the SV1 electromagnetic valve is closed, the RV1 electromagnetic valve is opened, the plunger pump B1 pumps brake fluid out of the energy accumulator A1, and the brake fluid enters the pressure building cavity through the RV1 electromagnetic valve and the PSV1 electromagnetic valve. For the energy accumulator A2, the SV2 electromagnetic valve is closed, the RV2 electromagnetic valve is opened, the plunger pump B2 pumps brake fluid out of the energy accumulator A2, and the brake fluid enters the pressure building cavity through the RV2 electromagnetic valve and the PSV2 electromagnetic valve. Because the increased braking force of the specific wheels can improve the hydraulic pressure in the ESC module, the hydraulic pressure of the ESC module is larger than the hydraulic pressure in the pressure build-up cavity, and the brake fluid can push back the piston and absorb the exceeded hydraulic pressure, so that the hydraulic pressure in the whole hydraulic loop is equal to the braking target value, and the stable and accurate braking pressure of the VDC system can be ensured when the VDC system works, thereby ensuring the safety and stability of the vehicle.
In this embodiment, in the dynamic control of the VDC system, when the braking force of the wheel end needs to be reduced, the step of opening the pressure release valve corresponding to the wheel end to release pressure further includes:
judging whether the braking force applied to the target wheel end is larger than a set braking force threshold value or not;
And responding to the fact that the braking force applied to the target wheel end is larger than a set braking force threshold value, opening a pressure release valve to release pressure according to a third control instruction issued by the VDC system, simultaneously controlling a plunger pump of the ESC module to cooperate with the pressure release valve to release pressure, and directly returning brake fluid of the wheel end to the pressure building cavity.
Specifically, the braking force applied to the target wheel end needs to be released after the wheel end is acted on. Normally, when the system pressure increases, the accumulator absorbs excess hydraulic energy and releases the stored hydraulic energy when necessary. Under certain working conditions, such as when the system needs to timely intervene in controlling the stability of the vehicle after emergency braking, the braking force of the wheel end needs to be rapidly reduced. At this time, the accumulator is used for pressure relief, and additional control logic and sensors may be added to monitor the state and pressure of the accumulator, and the response speed of the accumulator may not meet the requirement of rapid pressure relief, so a more direct pressure relief mode is required. In order to quickly release the braking force, firstly, the system judges whether the braking force applied to the target wheel end is larger than a set braking force threshold value, when the braking force is larger than the set braking force threshold value, the system can select to directly open a pressure relief electromagnetic valve of the wheel end, meanwhile, the system starts an ESC motor M2, plunger pumps (B1 and B2) start to work under the driving of the ESC motor M2, and brake fluid of the wheel end is directly pumped back into a pressure build-up cavity without passing through an accumulator. The pressure relief mode can reduce the braking force of the wheel end more quickly, and can relieve the liquid storage pressure of the energy accumulator.
It will be appreciated by those skilled in the art that in the above-described method of the specific embodiments, the written order of steps is not meant to imply a strict order of execution but rather should be construed according to the function and possibly inherent logic of the steps.
Based on the same inventive concept as the redundant vehicle dynamic control method described above, the embodiment of the present invention also provides a controller. Fig. 4 illustrates a physical schematic diagram of a controller, which may include a processor 310, a communication interface 320, a memory 330, and a communication bus 340, as shown in fig. 4, wherein the processor 310, the communication interface 320, and the memory 330 communicate with each other via the communication bus 340. The processor 310 may call a computer program in the memory 330 to perform the redundant vehicle dynamics control method as provided by the above-described embodiments.
The electronic hydraulic braking system can be an integrated electronic hydraulic braking system and can be a braking system of traffic vehicles such as electric vehicles, hybrid vehicles and the like. On low-adhesion roads (such as ice and snow roads), the electro-hydraulic braking system precisely controls the braking force and driving force of each wheel, and prevents the vehicle from sideslip and out of control. In emergency avoidance of obstacles, the driver is assisted in maintaining the vehicle steady by coordinating wheel braking and steering control. The electro-hydraulic braking system adjusts the yaw rate and lateral acceleration of the vehicle by coordinating wheel braking during high speed cornering to prevent understeer or oversteer of the vehicle.
The electro-hydraulic brake system may also provide a redundant control strategy. Under normal conditions, the VDC system intervenes, the braking pressure of each wheel is adjusted, the vehicle is helped to keep a stable running track, and when the motor of the linear control motor module fails, the ESC module can be started to boost. Or when the pressure build-up capability of the linear control motor module is insufficient, the ESC module can be used for supplementing liquid and boosting pressure. Or when a plurality of wheels are controlled to increase and decrease pressure simultaneously, the motor M1 and the ESC motor M2 of the linear control motor module can work synchronously, and the system can rapidly adjust the braking pressure of each wheel by accurately controlling the output of the two motors, so as to realize a quicker and smoother braking effect. The synchronous working capability not only improves the response speed of the braking system, but also enhances the stability and safety of the vehicle in emergency.
In summary, the method for dynamically controlling the redundant vehicle, the controller and the electronic hydraulic brake system provided by the embodiment of the application comprises the steps that an ECU control module monitors dynamic parameters in real time under the running state of the vehicle, wherein the dynamic parameters comprise the steering angle, the vehicle speed, the yaw rate and the lateral acceleration of the vehicle, analyzes the dynamic parameters and judges whether the activation condition of a VDC system is met, and when the activation condition is met, the ECU control module determines the braking force required by a target wheel controlled by the VDC system based on the steering condition of the vehicle, and further adjusts the braking of the target wheel through the VDC system, and the steering condition comprises oversteer and understeer. The application provides an effective solution for two working conditions of oversteering and understeering, and in the dynamic control process of the vehicle, the braking force of the wheels is regulated in a real-time closed loop manner by accurately controlling the braking force of the wheels. The system can respond to dynamic changes of the vehicle rapidly, adjust braking force in time, ensure stability of the vehicle in the running process, and accurately control application and release of the braking force through real-time closed-loop adjustment, so that unnecessary braking operation is avoided to cause abrasion and damage to a braking system.
The flowchart or block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of devices, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art can easily mention variations or alternatives within the scope of the present application. The present application is therefore to be considered in all respects as illustrative and not restrictive, and the scope of the application is indicated by the appended claims.
Claims (10)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202510065779.3A CN119459620A (en) | 2025-01-16 | 2025-01-16 | Redundant vehicle dynamic control method, controller and electronic hydraulic brake system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202510065779.3A CN119459620A (en) | 2025-01-16 | 2025-01-16 | Redundant vehicle dynamic control method, controller and electronic hydraulic brake system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN119459620A true CN119459620A (en) | 2025-02-18 |
Family
ID=94595025
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202510065779.3A Pending CN119459620A (en) | 2025-01-16 | 2025-01-16 | Redundant vehicle dynamic control method, controller and electronic hydraulic brake system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN119459620A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5857754A (en) * | 1996-02-02 | 1999-01-12 | Aisin Seiki Kabushiki Kaisha | Vehicle motion control system |
| CN105752059A (en) * | 2016-03-24 | 2016-07-13 | 江苏彤明高科汽车电器有限公司 | Vehicle stability control method |
| CN106427957A (en) * | 2015-08-11 | 2017-02-22 | 比亚迪股份有限公司 | Stabilization control system and stabilization control method based on four-wheel drive for electric vehicle, as well as electric vehicle |
| CN107662595A (en) * | 2016-07-30 | 2018-02-06 | 比亚迪股份有限公司 | A kind of vehicle braking stable control method and system |
| CN112519739A (en) * | 2020-11-06 | 2021-03-19 | 浙江零跑科技有限公司 | Split type electronic hydraulic braking system and method |
-
2025
- 2025-01-16 CN CN202510065779.3A patent/CN119459620A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5857754A (en) * | 1996-02-02 | 1999-01-12 | Aisin Seiki Kabushiki Kaisha | Vehicle motion control system |
| CN106427957A (en) * | 2015-08-11 | 2017-02-22 | 比亚迪股份有限公司 | Stabilization control system and stabilization control method based on four-wheel drive for electric vehicle, as well as electric vehicle |
| CN105752059A (en) * | 2016-03-24 | 2016-07-13 | 江苏彤明高科汽车电器有限公司 | Vehicle stability control method |
| CN107662595A (en) * | 2016-07-30 | 2018-02-06 | 比亚迪股份有限公司 | A kind of vehicle braking stable control method and system |
| CN112519739A (en) * | 2020-11-06 | 2021-03-19 | 浙江零跑科技有限公司 | Split type electronic hydraulic braking system and method |
Non-Patent Citations (1)
| Title |
|---|
| 裴晓飞，张成才，武冬梅: "《汽车电器与电控系统》", 31 August 2021, pages: 166 - 172 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8788172B2 (en) | Method and device for controlling an electrohydraulic braking system for motor vehicles | |
| JP4547793B2 (en) | Vehicle motion control device | |
| KR101977997B1 (en) | Method and system for regulating driving stability | |
| CN111278692B (en) | Vehicle brake control device | |
| EP2039573B1 (en) | Vehicle behavior control apparatus | |
| US20180029585A1 (en) | Vehicle controller, vehicle, and control system | |
| JP4277755B2 (en) | Vehicle turning control device | |
| JP5471078B2 (en) | Vehicle motion control device | |
| CN107697047B (en) | Brake control apparatus for vehicle | |
| CN107933536B (en) | Braking force control device | |
| JP4907306B2 (en) | Brake control device | |
| JPH0769188A (en) | Automatic brake device | |
| JP4828455B2 (en) | Brake control device | |
| CN119459620A (en) | Redundant vehicle dynamic control method, controller and electronic hydraulic brake system | |
| US8500219B2 (en) | Method and device for stabilizing a vehicle | |
| JP5769787B2 (en) | Brake control device | |
| JP3134716B2 (en) | Vehicle behavior control device | |
| US11104319B2 (en) | Braking control device for vehicle | |
| JP5446685B2 (en) | Vehicle motion control device | |
| KR20160142519A (en) | Apparatus for electronic stability control in a vehicle and control method thereof | |
| JP7302705B2 (en) | vehicle braking controller | |
| CN105813910A (en) | Method for operating brake system and brake system for motor vehicle | |
| US8825332B2 (en) | Method for stabilizing a vehicle in a driving situation in which the vehicle is simultaneously braked and steered | |
| US20220410860A1 (en) | Braking control device for vehicle | |
| JP2025058650A (en) | Brake Control Device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |