CN116238465A - Vehicle speed control method, device, equipment and readable storage medium - Google Patents
Vehicle speed control method, device, equipment and readable storage medium Download PDFInfo
- Publication number
- CN116238465A CN116238465A CN202310342734.7A CN202310342734A CN116238465A CN 116238465 A CN116238465 A CN 116238465A CN 202310342734 A CN202310342734 A CN 202310342734A CN 116238465 A CN116238465 A CN 116238465A
- Authority
- CN
- China
- Prior art keywords
- target
- speed
- vehicle speed
- retarder
- vehicle
- 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
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
- B60T8/17—Using electrical or electronic regulation means to control braking
- B60T8/172—Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
- B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
- B60T8/321—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration deceleration
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
- B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
- B60T8/72—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration responsive to a difference between a speed condition, e.g. deceleration, and a fixed reference
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/72—Electric energy management in electromobility
Landscapes
- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Transmission Of Braking Force In Braking Systems (AREA)
Abstract
The invention provides a vehicle speed control method, a device, equipment and a readable storage medium, wherein the method comprises the following steps: if the opening value of the vehicle brake pedal is changed from large to small, and when the opening value is smaller than a first threshold value, collecting the vehicle speed and setting the vehicle speed as a target vehicle speed; when the first speed difference between the actual speed of the vehicle and the target speed is larger than a second threshold value, determining a target braking moment of the retarder according to the target speed; and performing auxiliary braking according to the target braking moment of the retarder so as to control the vehicle speed. According to the invention, in the braking process of the vehicle, other electric control logic or sensors are not required to be added to the braking system, and only auxiliary braking is required to be carried out through the braking moment of the retarder, so that the control of the vehicle speed is achieved, and the abrasion to the brake shoe is avoided.
Description
Technical Field
The present invention relates to the field of automotive technologies, and in particular, to a vehicle speed control method, apparatus, device, and readable storage medium.
Background
During downhill travel of the vehicle, it is necessary to slow down or travel at a constant vehicle speed. The conventional way is to generate braking force by brake friction. However, the braking mode is also insufficient, and the brake is easy to generate high temperature due to overlong service time, so that the vehicle with braking failure is caused to have braking failure. In order to prevent the brake from excessively participating, an EBI function (a brake system is integrated with a retarder) in an electronic control brake EBS or ESC is adopted, an auxiliary brake function is fused with a conventional brake function, the hydraulic auxiliary brake is soft in intervention, the downhill braking process is more comfortable, the service brake is protected, and the abrasion of the shoe is reduced.
However, by combining this auxiliary braking function with the conventional braking function, other electronic control logic or sensors are added in addition to the braking system itself during braking of the vehicle, and wear on the shoes is unavoidable.
Disclosure of Invention
The invention mainly aims to provide a vehicle speed control method, a device, equipment and a readable storage medium, and aims to realize the control of the vehicle speed by only auxiliary braking through the braking moment of a retarder without adding other electric control logic or sensors to a braking system in the braking process of the vehicle, so that the abrasion of a brake shoe is avoided.
In a first aspect, the present invention provides a vehicle speed control method including:
if the opening value of the vehicle brake pedal is changed from large to small, and when the opening value is smaller than a first threshold value, collecting the vehicle speed and setting the vehicle speed as a target vehicle speed;
when the first speed difference between the actual speed of the vehicle and the target speed is larger than a second threshold value, determining a target braking moment of the retarder according to the target speed;
and performing auxiliary braking according to the target braking moment of the retarder so as to control the vehicle speed.
Optionally, the step of determining the target braking torque of the retarder according to the target vehicle speed includes:
substituting the target vehicle speed into a first formula, wherein the first formula is as follows:
wherein a ', b ', c ', d ', e ', f ', g ', h ' and i ' are constants; v (V) 0 Is the target speed; m is the weight of the vehicle; g is gravity acceleration;
is a slope angle; n is n e Engine speed; i.e e Is the speed ratio of the gearbox;
substituting the target vehicle speed into a second formula, wherein the second formula is as follows:
wherein j' is a constant; r is the tire radius; i.e 0 Is the speed ratio of the drive axle;
simultaneously solving the first formula and the second formula to obtain n e 、i e Multiple solutions of (2);
and substituting the multiple groups of solutions into a third formula to obtain braking torque of the plurality of retarders, wherein the third formula is as follows:
wherein T is he Is the braking torque of the retarder;
at maximum T he Is the target braking torque of the retarder.
Optionally, the step of performing auxiliary braking according to the target braking torque of the retarder to control the vehicle speed includes:
determining a target engine speed and a target gearbox speed ratio according to the target braking torque of the retarder;
determining a target transmission shaft rotation speed according to the target engine rotation speed and a target gearbox speed ratio;
and controlling the engine to reach the target engine speed according to the target transmission shaft speed, and controlling the gearbox to reach the target gearbox speed ratio so as to control the vehicle speed.
Optionally, after the step of determining the target engine speed and the target transmission speed ratio according to the target braking torque of the retarder, the method further includes:
detecting whether the target engine speed is greater than a third threshold;
if the target engine speed is not greater than a third threshold, executing the step of determining the target transmission shaft speed according to the target engine speed and the target gearbox speed ratio;
and if the target engine speed is greater than a third threshold, outputting an alarm prompt.
Optionally, after the step of performing auxiliary braking according to the target braking torque of the retarder to control the vehicle speed, the method further includes:
determining a theoretical deceleration duration according to the actual vehicle speed, the target engine speed and the target gearbox speed ratio;
adding a preset time length on the basis of the theoretical deceleration time length to obtain a target deceleration time length;
when the control duration reaches the target deceleration duration, acquiring a new actual vehicle speed, and detecting whether a second speed difference between the new actual vehicle speed and the target vehicle speed is smaller than a fourth threshold value, wherein the control duration is the duration for auxiliary braking;
and if the second speed difference is not smaller than the fourth threshold value, stopping executing the auxiliary braking step according to the target braking moment of the retarder, and outputting an alarm prompt.
Optionally, after the step of performing auxiliary braking according to the target braking torque of the retarder to control the vehicle speed, the method further includes:
collecting the temperature of a retarder;
detecting whether the temperature of the retarder is greater than a fifth threshold;
if the temperature of the retarder is greater than a fifth threshold value, the step of performing auxiliary braking according to the target braking moment of the retarder is stopped, and an alarm prompt is output.
In a second aspect, the present invention also provides a vehicle speed control device including:
the first determining module is used for acquiring the vehicle speed and setting the vehicle speed as a target vehicle speed if the opening value of the vehicle brake pedal is reduced from large to small and when the opening value is smaller than a first threshold value;
the second determining module is used for determining a target braking moment of the retarder according to the target vehicle speed when the first speed difference between the actual vehicle speed and the target vehicle speed is larger than a second threshold value;
and the control module is used for performing auxiliary braking according to the target braking moment of the retarder so as to control the vehicle speed.
In a third aspect, the present invention also provides a vehicle speed control apparatus comprising a processor, a memory, and a vehicle speed control program stored on the memory and executable by the processor, wherein the vehicle speed control program, when executed by the processor, implements the steps of the vehicle speed control method as described above.
In a fourth aspect, the present invention also provides a readable storage medium having stored thereon a vehicle speed control program, wherein the vehicle speed control program, when executed by a processor, implements the steps of the vehicle speed control method as described above.
In the invention, if the opening value of a vehicle brake pedal is changed from large to small, and when the opening value is smaller than a first threshold value, collecting the vehicle speed and setting the vehicle speed as a target vehicle speed; when the first speed difference between the actual speed of the vehicle and the target speed is larger than a second threshold value, determining a target braking moment of the retarder according to the target speed; and performing auxiliary braking according to the target braking moment of the retarder so as to control the vehicle speed. According to the invention, in the braking process of the vehicle, other electric control logic or sensors are not required to be added to the braking system, and only auxiliary braking is required to be carried out through the braking moment of the retarder, so that the control of the vehicle speed is achieved, and the abrasion to the brake shoe is avoided.
Drawings
FIG. 1 is a flow chart of a first embodiment of a vehicle speed control method according to the present invention;
FIG. 2 is a graph showing a relationship between a braking torque of a test retarder and a rotational speed of a transmission shaft according to an embodiment of the present invention;
FIG. 3 is a schematic diagram illustrating a process of performing auxiliary braking by a target braking torque of a retarder according to an embodiment of the present invention
FIG. 4 is a flow chart of a second embodiment of the vehicle speed control method of the present invention;
FIG. 5 is a schematic diagram of functional blocks of a vehicle speed control device according to an embodiment of the present invention;
fig. 6 is a schematic hardware configuration of a vehicle speed control apparatus according to an embodiment of the present invention.
The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.
Detailed Description
It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
In a first aspect, an embodiment of the present invention provides a vehicle speed control method.
Referring to fig. 1, fig. 1 is a flowchart of a vehicle speed control method according to a first embodiment of the present invention. As shown in fig. 1, in one embodiment, a vehicle speed control method includes:
step S10, if the opening value of a vehicle brake pedal is reduced from large to small, and when the opening value is smaller than a first threshold value, acquiring the vehicle speed and setting the vehicle speed as a target vehicle speed;
in this embodiment, when the opening value of the brake pedal changes from large to small, it is detected whether the opening value of the brake pedal is smaller than a first threshold; if the opening value of the brake pedal is smaller than the first threshold value, the target speed of the vehicle is further determined. For example, in this embodiment, the first threshold may be 5%, and when the opening value of the brake pedal changes from large to small, it is determined that the user is loosening the brake pedal; if the opening value of the brake pedal is smaller than 5%, determining the target speed of the vehicle by recording the current speed of the vehicle, namely the speed of the vehicle after the vehicle is decelerated and stabilized. The numerical value "5%" exemplified in this example is only for explanation of this example, and is not a limiting value.
Step S20, when the first speed difference between the actual speed of the vehicle and the target speed is larger than a second threshold value, determining the target braking moment of the retarder according to the target speed;
in the embodiment, whether a first speed difference between the actual speed of the vehicle and the target speed is larger than a second threshold value is detected; and when the first speed difference between the actual speed of the vehicle and the target speed is larger than the second threshold value, further determining the target braking moment of the retarder according to the target speed. For example, in this embodiment, the first speed difference may be 10km/h, the second threshold may be 5km/h, and in order to ensure the stability of the vehicle speed, the speed difference between the actual vehicle speed and the target vehicle speed is relatively stable at the speed of 5km/h, and when the speed difference between the actual vehicle speed and the target vehicle speed is 10km/h and is greater than the second threshold of 5km/h, the vehicle may determine the target braking torque of the retarder through the target speed. The values "10km/h" and "5km/h" in the present embodiment are merely for explanation of the present embodiment, and are not limiting values.
Further, in an embodiment, the step of determining the target braking torque of the retarder according to the target vehicle speed includes:
substituting the target vehicle speed into a first formula, wherein the first formula is as follows:
wherein a ', b ', c ', d ', e ', f ', g ', h ' and i ' are constants; v (V) 0 Is the target speed; m is the weight of the vehicle; g is gravity acceleration;
is a slope angle; n is n e Engine speed; i.e e Is the speed ratio of the gearbox;
substituting the target vehicle speed into a second formula, wherein the second formula is as follows:
wherein j' is a constant; r is the tire radius; i.e 0 Is the speed ratio of the drive axle;
simultaneously solving the first formula and the second formula to obtain n e 、i e Multiple solutions of (2);
and substituting the multiple groups of solutions into a third formula to obtain braking torque of the plurality of retarders, wherein the third formula is as follows:
wherein T is he Is the braking torque of the retarder;
at maximum T he Is the target braking torque of the retarder.
In the embodiment, according to the target vehicle speed, the target braking moment of the retarder is further determined;
for example: according to the driving force balance equation:
W hair brush ＝(W Total (S) -W Wind power -W Rolling machine ) /(1+η) … … … … … … … … … … … … … … (equation 1)
W Total (S) ＝F Total (S) V 0 … … … … … … … … … … … … … … … … … … (equation 3)
The formulas for obtaining auxiliary braking power by combining the formula 1, the formula 2 and the formula 3 are as follows:
another formula for auxiliary braking power is:
wherein W is Total (S) Is the total power; v (V) 0 To set the vehicle speed; w (W) Wind power Taking 1.95kw for the air resistance power; w (W) Rolling machine ＝mg*Cr*V 0 (m is the vehicle mass, g is the gravitational acceleration, cr is the rolling resistance coefficient and takes 0.01); w (W) Hair brush : is auxiliary braking power; η: the loss efficiency is 0.15;
slope angle.
The formula of the braking torque of the retarder is:
T he ＝λρgD 5 (n e i e ) 2 … … … … … … … … … … … … … … … … (equation 6)
Wherein T is he Is the braking torque of the retarder; lambda is a braking torque coefficient; ρ is the working fluid density; d is the effective diameter of the circle; n is n e Engine speed; i.e e Is the speed ratio of the gearbox.
Combining equation 3, equation 4 and equation 5 yields the following equations:
referring to fig. 2, fig. 2 is a schematic diagram of a relationship between a braking torque and a rotational speed of a transmission shaft of a test retarder according to an embodiment of the invention. As shown in fig. 2, the approximate formula obtained by fitting the retarder characteristic curve is as follows:
combining equation 7 and equation 8 yields the following equation:
the following formula can be derived from the tire radius and the transaxle speed ratio:
wherein i is 0 Is the speed ratio of the drive axle; r is the tire radius.
According to the corresponding relation among the vehicle speed, the engine speed and the speed ratio of the speed change box, the vehicle speed range corresponding to each speed ratio of the speed change box is further determined, so that under the condition that the target speed is a fixed value, fixed values of a plurality of speed ratio of the speed change box can be obtained.
Simultaneous solving of equation 9 and equation 10 yields n e 、i e Multiple solutions of (2);
substituting the solutions into an approximate formula obtained by retarder characteristic curve fitting, namely formula 8, respectively to obtain braking moments of a plurality of retarders;
at maximum T he Is the target braking torque of the retarder.
Step S30, auxiliary braking is carried out according to the target braking moment of the retarder so as to control the speed of the vehicle;
in this embodiment, according to the target braking force of the retarder, the vehicle is further braked in an auxiliary manner, so as to control the vehicle speed. For example, a target braking torque of the retarder is calculated, the braking torque is regulated through a hydraulic torque converter in the retarder, auxiliary braking is carried out on the vehicle, and then the vehicle speed is controlled.
In an embodiment, referring to fig. 3, fig. 3 is a schematic flow chart of auxiliary braking performed by a target braking torque of a retarder according to an embodiment of the invention. As shown in fig. 3, the vehicle speed control method includes:
further, in an embodiment, step S30 includes:
step S301, determining a target engine speed and a target gearbox speed ratio according to a target braking torque of the retarder;
in this embodiment, the target engine speed and the target gearbox speed ratio are further determined according to the target braking torque of the retarder. For example: at n e 、i e In the multiple groups of solutions of (1), with the maximum T he Is the target braking moment of the retarder, and corresponds to n respectively at the moment e And i e Will n e Is determined as the target engine speed, i e Is determined as the target transmission ratio.
Step S302, determining the rotation speed of a target transmission shaft according to the target engine rotation speed and the target speed ratio of the gearbox;
in the embodiment, the target transmission shaft rotating speed is further determined according to the corresponding relation between the transmission shaft rotating speed, the engine rotating speed and the speed ratio of the gearbox; for example, the propeller shaft speed is a product of the engine speed and the transmission speed ratio, and the target propeller shaft speed is determined from the target engine speed and the target transmission speed ratio.
Step S303, according to the target rotation speed of the transmission shaft, controlling the engine to reach the target rotation speed of the engine, and controlling the gearbox to reach the target speed ratio of the gearbox so as to control the speed of the vehicle.
In this embodiment, the target braking torque of the retarder acts on the rotating shaft, controlling the drive shaft to reach the target drive shaft rotational speed, the drive shaft further controlling the engine to reach the target engine rotational speed, and controlling the gearbox to reach the target gearbox speed ratio. For example, the target braking torque of the retarder gives a reaction force to the drive shaft, controls the drive shaft to reach a target drive shaft speed, and further controls the engine to reach the target engine speed, and controls the gearbox to reach a target gearbox speed ratio to control the vehicle speed to reach a target vehicle speed.
Further, in an embodiment, after the step of determining the target engine speed and the target transmission speed ratio according to the target braking torque of the retarder, the method further includes:
detecting whether the target engine speed is greater than a third threshold;
if the target engine speed is not greater than a third threshold, executing the step of determining the target transmission shaft speed according to the target engine speed and the target gearbox speed ratio; and if the target engine speed is greater than a third threshold, outputting an alarm prompt.
In this embodiment, according to the determined target engine speed, whether the target engine speed is greater than a third threshold value is further detected; if the target engine speed is not greater than the third threshold value, further determining the target transmission shaft speed; and if the target engine speed is greater than a third threshold, outputting an alarm prompt, wherein the third threshold is the maximum safe speed of the engine. For example, the third threshold may be 4000rad/min, the target engine speed may be 5000rad/min, and the target propeller shaft is further determined based on the target engine speed and the target case speed ratio when the target engine speed is not greater than 4000 rad/min; if the rotation speed of the target engine is 5000rad/min and the maximum safe rotation speed of the engine is 4000rad/min, outputting an alarm prompt, if an auxiliary brake switch of a vehicle instrument always blinks, suspending a brake function of a retarder, prompting that the gradient of a road in front is overlarge or the target speed is too fast, and the like. The values "4000rad/min" and "5000rad/min" in the present embodiment are merely for the purpose of illustrating the present embodiment, and are not limiting values.
Further, in an embodiment, referring to fig. 4, fig. 4 is a flowchart of a second embodiment of the vehicle speed control method according to the present invention. As shown in fig. 4, after step S30, the vehicle speed control method includes:
step S40, determining theoretical deceleration duration according to the actual vehicle speed, the target engine speed and the target gearbox speed ratio;
step S50, adding a preset time length on the basis of the theoretical deceleration time length to obtain a target deceleration time length;
in this embodiment, to ensure that the braking torque of the retarder is effective for performing auxiliary braking, a theoretical deceleration duration Δt may be further determined according to the actual vehicle speed, the target engine speed, and the target gearbox speed ratio, where the theoretical deceleration duration is a theoretical duration for the retarder to control the vehicle speed to reach the target vehicle speed. In practice, in the process of controlling the vehicle speed, a certain error exists, and the target deceleration duration is further obtained by adding a preset duration to the theoretical deceleration duration. For example, the pressure equation for an engine is:
F hair brush ＝W Hair brush /V 0 =ma … … … … … … … … … … … (equation 11)
Combining equation 11 and equation 5 yields the following equation:
and further obtaining theoretical deceleration duration delta t according to the actual vehicle speed, the target engine speed and the target gearbox speed ratio, wherein the formula is as follows:
at this time, if the theoretical deceleration duration is 5s and the preset duration is 1s, the theoretical deceleration duration and the preset duration are added to determine that the target deceleration duration is 6s, that is, the target duration of auxiliary braking of the target braking moment of the retarder is 6s, so as to control the vehicle speed. The values "5s", "1s" and "6s" in this embodiment are merely for illustration of this embodiment, and are not limiting values.
Step S60, when the control duration reaches the target deceleration duration, acquiring a new actual vehicle speed, and detecting whether a second speed difference between the new actual vehicle speed and the target vehicle speed is smaller than a fourth threshold value, wherein the control duration is the actual duration for auxiliary braking;
and step S70, if the second speed difference is not smaller than the fourth threshold value, stopping executing the auxiliary braking step according to the target braking moment of the retarder, and outputting an alarm prompt.
In this embodiment, when the vehicle control duration reaches the target deceleration duration, it is detected whether a second speed difference between a new actual vehicle speed and the target vehicle speed is smaller than a fourth threshold, and if the second speed difference is not smaller than the fourth threshold, the vehicle pauses to execute the auxiliary braking operation by the braking torque of the retarder, and sends out alarm information. The control duration is a duration of auxiliary braking of the vehicle, and the fourth threshold value is a range value which is not different from the target speed. For example, the target vehicle speed may be 30km/h, the new actual vehicle speed may be 31km/h, the fourth threshold may be 0.5km/h, when the control duration of the vehicle reaches 6s, the speed difference between the new actual vehicle speed 31km/h and the target vehicle speed 30km/h is not less than 0.5km/h, it is further determined that the auxiliary braking function of the vehicle is invalid, the vehicle pauses to execute the auxiliary braking operation of the target braking moment of the retarder, and outputs an alarm prompt, for example, the auxiliary braking switch of the vehicle instrument always blinks, the braking function of the retarder pauses, the instrument popup window or the voice prompt retarder is limited in function, and signals such as a brake pedal is stamped down. The values "30km/h", "31km/h" and "0.5km/h" in the present embodiment are merely for illustration of the present embodiment, and are not limiting values.
Further, in an embodiment, after step S30, the method further includes:
collecting the temperature of a retarder; detecting whether the temperature of the retarder is greater than a fifth threshold; if the temperature of the retarder is greater than a fifth threshold value, the step of performing auxiliary braking according to the target braking moment of the retarder is stopped, and an alarm prompt is output.
In this embodiment, the temperature of the retarder (may be the temperature of the retarder itself or the temperature of liquid or gas around the retarder) is collected, whether the temperature of the retarder is greater than a fifth threshold is detected, if the temperature of the retarder is greater than the fifth threshold, the operation of suspending the execution of the target braking torque of the retarder to perform auxiliary braking is further determined, and an alarm prompt is output, where the fifth threshold is the maximum safe temperature of the retarder. For example, the fifth threshold may be 95 ℃, detect whether the temperature of the retarder is greater than 95 ℃, if the temperature of the retarder is currently 100 ℃ greater than 95 ℃, determine to suspend the execution of the operation of the auxiliary braking by the target braking torque of the retarder, and output an alarm prompt, such as the signals that the auxiliary braking switch of the vehicle instrument always blinks, the braking function of the retarder is suspended, the instrument popup window or the voice prompts that the temperature of the retarder is too high, the function of the retarder is limited, and the brake pedal is depressed. The values "100 ℃ and" 95 ℃ in the present embodiment are only for explaining the present embodiment, and are not limiting values.
Further, in an embodiment, after step S30, the method further includes:
and when an auxiliary braking function closing instruction is received, stopping executing the auxiliary braking according to the target braking moment of the retarder.
In this embodiment, when the vehicle receives the command for turning off the auxiliary braking function, it is further determined to suspend the execution of the target braking torque of the retarder to perform the auxiliary braking operation. For example, the user manually closes the auxiliary brake switch, and the vehicle does not perform auxiliary braking by the braking torque of the retarder after receiving an auxiliary brake function closing instruction.
In a second aspect, the embodiment of the invention further provides a vehicle speed control device.
In an embodiment, referring to fig. 5, fig. 5 is a schematic functional block diagram of a vehicle speed control device according to an embodiment of the present invention. As shown in fig. 5, the vehicle speed control device includes:
a first determining module 10, configured to collect a vehicle speed and set the vehicle speed as a target vehicle speed if an opening value of a brake pedal of the vehicle is reduced from large to small and when the opening value is smaller than a first threshold;
a second determining module 20, configured to determine a target braking torque of the retarder according to the target vehicle speed when a first speed difference between an actual vehicle speed and the target vehicle speed is greater than a second threshold;
and the control module 30 is used for performing auxiliary braking according to the target braking moment of the retarder so as to control the vehicle speed.
Further, in an embodiment, the second determining module 20 is specifically configured to:
substituting the target vehicle speed into a first formula, wherein the first formula is as follows:
wherein a ', b ', c ', d ', e ', f ', g ', h ' and i ' are constants; v (V) 0 Is the target speed; m is the weight of the vehicle; g is gravity acceleration;
is a slope angle; n is n e Engine speed; i.e e Is the speed ratio of the gearbox;
substituting the target vehicle speed into a second formula, wherein the second formula is as follows:
wherein j' is a constant; r is the tire radius; i.e 0 Is the speed ratio of the drive axle;
simultaneously solving the first formula and the second formula to obtain n e 、i e Multiple solutions of (2);
and substituting the multiple groups of solutions into a third formula to obtain braking torque of the plurality of retarders, wherein the third formula is as follows:
wherein T is he Is the braking torque of the retarder;
at maximum T he Is the target braking torque of the retarder.
Further, in one embodiment, the control module 30 is specifically configured to:
determining a target engine speed and a target gearbox speed ratio according to the target braking torque of the retarder;
determining a target transmission shaft rotation speed according to the target engine rotation speed and a target gearbox speed ratio;
and controlling the engine to reach the target engine speed according to the target transmission shaft speed, and controlling the gearbox to reach the target gearbox speed ratio so as to control the vehicle speed.
Further, in an embodiment, the vehicle speed control device further includes: a first detection module for:
detecting whether the target engine speed is greater than a third threshold;
if the target engine speed is not greater than a third threshold, executing the step of determining the target transmission shaft speed according to the target engine speed and the target gearbox speed ratio;
if the target engine speed is greater than a third threshold, outputting an alarm reminding
Further, in an embodiment, the second determining module 20 is further configured to:
determining a theoretical deceleration duration according to the actual vehicle speed, the target engine speed and the target gearbox speed ratio;
adding a preset time length on the basis of the theoretical deceleration time length to obtain a target deceleration time length;
when the control duration reaches the target deceleration duration, acquiring a new actual vehicle speed, and detecting whether a second speed difference between the new actual vehicle speed and the target vehicle speed is smaller than a fourth threshold value, wherein the control duration is the duration for auxiliary braking;
and if the second speed difference is not smaller than the fourth threshold value, stopping executing the auxiliary braking step according to the target braking moment of the retarder, and outputting an alarm prompt.
Further, in an embodiment, the vehicle speed control device further includes: a second detection module for:
collecting the temperature of a retarder;
detecting whether the temperature of the retarder is greater than a fifth threshold;
if the temperature of the retarder is greater than a fifth threshold value, the step of performing auxiliary braking according to the target braking moment of the retarder is stopped, and an alarm prompt is output.
Further, in an embodiment, the control module 30 is further configured to:
and when an auxiliary braking function closing instruction is received, stopping executing the auxiliary braking according to the target braking moment of the retarder.
The function implementation of each module in the vehicle speed control device corresponds to each step in the vehicle speed control method embodiment, and the function and implementation process of each module are not described in detail herein.
In a third aspect, an embodiment of the present invention provides a vehicle speed control apparatus that may be a personal computer (personal computer, PC), a notebook computer, a server, or the like having a data processing function.
Referring to fig. 6, fig. 6 is a schematic hardware configuration of a vehicle speed control apparatus according to an embodiment of the present invention. In an embodiment of the present invention, the vehicle speed control apparatus may include a processor 1001 (e.g., a central processing unit Central Processing Unit, CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Wherein the communication bus 1002 is used to enable connected communications between these components; the user interface 1003 may include a Display screen (Display), an input unit such as a Keyboard (Keyboard); the network interface 1004 may optionally include a standard wired interface, a WIreless interface (e.g., WIreless-FIdelity, WI-FI interface); the memory 1005 may be a high-speed random access memory (random access memory, RAM) or a stable memory (non-volatile memory), such as a disk memory, and the memory 1005 may alternatively be a storage device independent of the processor 1001. Those skilled in the art will appreciate that the hardware configuration shown in fig. 6 is not limiting of the invention and may include more or fewer components than shown, or may combine certain components, or a different arrangement of components.
With continued reference to fig. 6, an operating system, a network communication module, a user interface module, and a vehicle speed control program may be included in the memory 1005, which is one type of computer storage medium in fig. 6. The processor 1001 may call a vehicle speed control program stored in the memory 1005, and execute the vehicle speed control method provided by the embodiment of the present invention.
In a fourth aspect, embodiments of the present invention also provide a readable storage medium.
The readable storage medium of the present invention stores a vehicle speed control program, wherein the vehicle speed control program, when executed by a processor, implements the steps of the vehicle speed control method as described above.
The method implemented when the vehicle speed control program is executed may refer to various embodiments of the vehicle speed control method of the present invention, and will not be described herein.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.
The foregoing embodiment numbers of the present invention are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.
From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) as described above, comprising several instructions for causing a terminal device to perform the method according to the embodiments of the present invention.
The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the scope of the invention, but rather is intended to cover any equivalents of the structures or equivalent processes disclosed herein or in the alternative, which may be employed directly or indirectly in other related arts.
Claims (10)
1. A vehicle speed control method, characterized by comprising:
if the opening value of the vehicle brake pedal is changed from large to small, and when the opening value is smaller than a first threshold value, collecting the vehicle speed and setting the vehicle speed as a target vehicle speed;
when the first speed difference between the actual speed of the vehicle and the target speed is larger than a second threshold value, determining a target braking moment of the retarder according to the target speed;
and performing auxiliary braking according to the target braking moment of the retarder so as to control the vehicle speed.
2. The vehicle speed control method according to claim 1, characterized in that the step of determining a target braking torque of the retarder according to the target vehicle speed includes:
substituting the target vehicle speed into a first formula, wherein the first formula is as follows:
wherein a ', b ', c ', d ', e ', f ', g ', h ' and i ' are constants; v (V) 0 Is the target speed; m is the weight of the vehicle; g is gravity acceleration;
is a slope angle; n is n e Engine speed; i.e e Is the speed ratio of the gearbox;
substituting the target vehicle speed into a second formula, wherein the second formula is as follows:
wherein j' is a constant; r is the tire radius; i.e 0 Is the speed ratio of the drive axle;
simultaneously solving the first formula and the second formula to obtain n e 、i e Multiple solutions of (2);
and substituting the multiple groups of solutions into a third formula to obtain braking torque of the plurality of retarders, wherein the third formula is as follows:
wherein T is he Is the braking torque of the retarder;
at maximum T he Is the target braking torque of the retarder.
3. The vehicle speed control method according to claim 1, characterized in that the step of performing auxiliary braking according to a target braking torque of the retarder to control the vehicle speed includes:
determining a target engine speed and a target gearbox speed ratio according to the target braking torque of the retarder;
determining a target transmission shaft rotation speed according to the target engine rotation speed and a target gearbox speed ratio;
and controlling the engine to reach the target engine speed according to the target transmission shaft speed, and controlling the gearbox to reach the target gearbox speed ratio so as to control the vehicle speed.
4. A vehicle speed control method as claimed in claim 3, further comprising, after said step of determining a target engine speed and a target transmission speed ratio from a target braking torque of said retarder:
detecting whether the target engine speed is greater than a third threshold;
if the target engine speed is not greater than a third threshold, executing the step of determining the target transmission shaft speed according to the target engine speed and the target gearbox speed ratio;
and if the target engine speed is greater than a third threshold, outputting an alarm prompt.
5. A vehicle speed control method according to claim 3, characterized by further comprising, after the step of performing auxiliary braking according to the target braking torque of the retarder to control the vehicle speed:
determining a theoretical deceleration duration according to the actual vehicle speed, the target engine speed and the target gearbox speed ratio;
adding a preset time length on the basis of the theoretical deceleration time length to obtain a target deceleration time length;
when the control duration reaches the target deceleration duration, acquiring a new actual vehicle speed, and detecting whether a second speed difference between the new actual vehicle speed and the target vehicle speed is smaller than a fourth threshold value, wherein the control duration is the duration for auxiliary braking;
and if the second speed difference is not smaller than the fourth threshold value, stopping executing the auxiliary braking step according to the target braking moment of the retarder, and outputting an alarm prompt.
6. The vehicle speed control method according to any one of claims 1 to 5, characterized by further comprising, after the step of performing auxiliary braking according to the target braking torque of the retarder to control the vehicle speed:
collecting the temperature of a retarder;
detecting whether the temperature of the retarder is greater than a fifth threshold;
if the temperature of the retarder is greater than a fifth threshold value, the step of performing auxiliary braking according to the target braking moment of the retarder is stopped, and an alarm prompt is output.
7. The vehicle speed control method according to any one of claims 1 to 5, characterized by further comprising, after the step of performing auxiliary braking according to the target braking torque of the retarder to control the vehicle speed:
and when an auxiliary braking function closing instruction is received, stopping executing the auxiliary braking according to the target braking moment of the retarder.
8. A vehicle speed control device, characterized by comprising:
the first determining module is used for acquiring the vehicle speed and setting the vehicle speed as a target vehicle speed if the opening value of the vehicle brake pedal is reduced from large to small and when the opening value is smaller than a first threshold value;
the second determining module is used for determining a target braking moment of the retarder according to the target vehicle speed when the first speed difference between the actual vehicle speed and the target vehicle speed is larger than a second threshold value;
and the control module is used for performing auxiliary braking according to the target braking moment of the retarder so as to control the vehicle speed.
9. A vehicle speed control apparatus comprising a processor, a memory, and a vehicle speed control program stored on the memory and executable by the processor, wherein the vehicle speed control program, when executed by the processor, implements the steps of the vehicle speed control method according to any one of claims 1 to 7.
10. A readable storage medium, wherein a vehicle speed control program is stored on the readable storage medium, wherein the vehicle speed control program, when executed by a processor, implements the steps of the vehicle speed control method according to any one of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310342734.7A CN116238465A (en) | 2023-03-31 | 2023-03-31 | Vehicle speed control method, device, equipment and readable storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310342734.7A CN116238465A (en) | 2023-03-31 | 2023-03-31 | Vehicle speed control method, device, equipment and readable storage medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116238465A true CN116238465A (en) | 2023-06-09 |
Family
ID=86631400
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310342734.7A Pending CN116238465A (en) | 2023-03-31 | 2023-03-31 | Vehicle speed control method, device, equipment and readable storage medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116238465A (en) |
-
2023
- 2023-03-31 CN CN202310342734.7A patent/CN116238465A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5231900B2 (en) | Method for controlling vehicle power system | |
| CN107415704B (en) | Composite braking method and device and adaptive cruise controller | |
| KR20200068156A (en) | Vehicle and control method for the same | |
| US10940859B2 (en) | Automatic speed control and method for the autonomous speed control of a vehicle | |
| CN108656956A (en) | Electric vehicle brake method, system and electric vehicle | |
| KR20190017343A (en) | Method and Apparatus for Controlling for Autonomous Driving of Electric Vehicle | |
| CN111959285A (en) | Electric vehicle energy recovery method, equipment, storage medium and device | |
| WO2013153597A1 (en) | Vehicle power-generator device and vehicle power-generation control method | |
| CN112757909B (en) | Vehicle control method and device, electronic equipment and storage medium | |
| US20100312448A1 (en) | Method for detecting wheel slip | |
| CN112874520B (en) | Vehicle control method, device, equipment and storage medium | |
| CN109969186B (en) | Method and control device for operating an electric or hybrid vehicle | |
| CN108025707A (en) | Method for making commercial car slow down | |
| CN116238465A (en) | Vehicle speed control method, device, equipment and readable storage medium | |
| CN115009239B (en) | Parking method, device, equipment and storage medium for vehicle | |
| CN116039589A (en) | Brake control method, device, equipment and storage medium | |
| JP2006036196A (en) | Control method and device of inside and outside brake for decelerating vehicle in bend travelling | |
| EP3725613B1 (en) | Vehicle control method and vehicle control apparatus | |
| CN114003024A (en) | Following vehicle speed planning method and device based on vehicle formation and automobile | |
| CN112109554A (en) | Method and device for controlling regenerative braking, storage medium and vehicle | |
| CN113147712B (en) | Adaptive braking method, device, equipment and storage medium | |
| JP7272215B2 (en) | Control device | |
| CN113753016B (en) | Method, equipment, storage medium and device for controlling running of hybrid electric vehicle on bumpy road surface | |
| CN113984390B (en) | Driving force adjustment method, device and system applied to thermal balance test | |
| CN116588103A (en) | Method and device for controlling vehicle to run and intelligent vehicle |
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 |