CN112113779A - Wheel friction coefficient detection method, detection terminal and storage medium - Google Patents
Wheel friction coefficient detection method, detection terminal and storage medium Download PDFInfo
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Abstract
The invention discloses a wheel friction coefficient detection method, a detection terminal and a storage medium, wherein the method comprises the following steps: acquiring the vehicle weight, the wheel radius and the gravity acceleration; acquiring the output torque of an engine, the angular speeds of driving wheels and driven wheels on the left side and the right side according to a preset sampling frequency; respectively calculating and storing a left-side slip rate and a right-side slip rate at each sampling moment according to the angular speeds of the driving wheel and the driven wheel at the left side and the right side acquired at each sampling moment, and calculating and storing a driving shaft friction coefficient at each sampling moment according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque acquired at each sampling moment; and obtaining the maximum friction coefficient of the wheel according to the stored driving shaft friction coefficient, the left side slip rate and the right side slip rate corresponding to at least two sampling moments. The invention can obtain the gradient of the ramp without additionally arranging a gradient sensor, thereby reducing the manufacturing cost of the vehicle.
Description
Technical Field
The invention relates to the field of vehicle detection, in particular to a wheel friction coefficient detection method, a detection terminal and a computer-readable storage medium.
Background
At present, most of the detection methods for the friction coefficient of the vehicle tire are provided with a special sensor to measure relevant parameters of the tire and calculate the friction coefficient. However, the need to additionally provide a dedicated sensor for measuring tire related parameters increases the cost of the vehicle and does not allow the maximum coefficient of friction of the wheel to be estimated.
Disclosure of Invention
The invention mainly aims to provide a wheel friction coefficient detection method, a detection terminal and a computer readable storage medium, aiming at solving the problem that the existing detection of the friction coefficient of a vehicle tire needs to be additionally provided with a special sensor, so that the cost of an automobile is increased.
In order to achieve the above object, the present invention provides a method for detecting a friction coefficient of a wheel, comprising the steps of:
acquiring the vehicle weight, the wheel radius and the gravity acceleration;
acquiring the output torque of an engine, the angular speeds of driving wheels and driven wheels on the left side and the right side of the engine according to a preset sampling frequency;
respectively calculating and storing a left side slip rate and a right side slip rate corresponding to each sampling moment according to the angular velocity of the driving wheel and the angular velocity of the driven wheel on the left side and the right side acquired at each sampling moment, and calculating and storing a driving shaft friction coefficient corresponding to each sampling moment according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque acquired at each sampling moment;
and obtaining the maximum friction coefficient of the wheel according to the stored driving shaft friction coefficient, the left side slip rate and the right side slip rate corresponding to at least two sampling moments.
Optionally, the step of calculating and storing a left-side slip rate and a right-side slip rate corresponding to each sampling time according to the angular velocity of the driving wheel and the angular velocity of the driven wheel on the left and right sides acquired at each sampling time, respectively, and the step of calculating and storing a driving shaft friction coefficient corresponding to each sampling time according to the vehicle weight, the wheel radius, the gravitational acceleration, and the engine output torque acquired at each sampling time includes:
respectively calculating a left side slip rate and a right side slip rate corresponding to each sampling moment according to the angular speed of the driving wheel and the angular speed of the driven wheel on the left side and the right side acquired at each sampling moment, and calculating a driving shaft friction coefficient corresponding to each sampling moment according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque acquired at each sampling moment;
respectively judging whether the left side slip rate and the right side slip rate corresponding to each sampling moment are in a preset slip rate range and whether the driving shaft friction coefficient corresponding to each sampling moment is in a preset friction coefficient range;
and if the driving shaft friction coefficient corresponding to the sampling moment is in the preset friction coefficient range and the left side slip rate and the right side slip rate corresponding to the sampling moment are both in the preset slip rate range, storing the driving shaft friction coefficient, the left side slip rate and the right side slip rate corresponding to the sampling moment.
Optionally, the step of calculating a left-side slip rate and a right-side slip rate corresponding to each sampling time according to the angular velocity of the driving wheel and the angular velocity of the driven wheel at the left and right sides acquired at each sampling time respectively includes:
calculating a left side slip rate corresponding to each sampling moment according to a preset left side slip rate calculation formula, the left side driving wheel angular speed and the left side driven wheel angular speed acquired at each sampling moment, wherein the preset left side slip rate calculation formula is as follows:
Sleft side of＝(vLeft slave-vLeft main)/vLeft mainWherein v isLeft slaveLeft-hand driven wheel angular velocity, v, acquired for each sampling instantLeft mainLeft active wheel angular velocity, S, collected for each sampling instantLeft side ofThe left side slip rate corresponding to each sampling time is obtained;
according to a preset right side slip rate calculation formula, and the input of the right side driving wheel angular speed and the right side driven wheel angular speed acquired at each sampling moment, calculating the right side slip rate corresponding to each sampling moment, wherein the preset right side slip rate calculation formula is as follows:
Sright side＝(vRight slave-vRight main)/vRight mainWherein v isRight slaveThe angular velocity, v, of the driven wheel on the right acquired for each sampling instantRight mainThe right-hand active wheel angular velocity, S, collected for each sampling instantRight sideThe right slip rate corresponding to each sampling time.
Optionally, the step of calculating a friction coefficient of the driving shaft corresponding to each sampling time according to the vehicle weight, the wheel radius, the gravitational acceleration and the engine output torque collected at each sampling time includes:
calculating a driving shaft friction coefficient corresponding to each sampling moment according to a preset driving shaft friction coefficient calculation formula, the vehicle weight, the wheel radius and the engine output torque collected at each sampling moment, wherein the preset driving shaft friction coefficient calculation formula is as follows:
and u is T/(r m g), wherein T is the engine output torque collected at each sampling moment, r is the radius of the wheel, m is the weight of the vehicle body, g is the gravity acceleration, and u is the friction coefficient of the driving shaft corresponding to each sampling moment.
Optionally, the step of obtaining the maximum friction coefficient of the wheel according to the stored driving shaft friction coefficient, the left-side slip ratio and the right-side slip ratio corresponding to the at least two sampling moments comprises:
obtaining the maximum friction coefficient of the left wheel according to the stored drive shaft friction coefficients and left slip rates corresponding to at least two sampling moments;
obtaining the maximum friction coefficient of the right wheel according to the stored driving shaft friction coefficient and the right slip ratio corresponding to at least two sampling moments;
judging whether the difference value between the maximum friction coefficient of the left wheel and the maximum friction coefficient of the right wheel is smaller than a preset threshold value or not;
if so, taking the average value of the maximum friction coefficient of the left wheel and the maximum friction coefficient of the right wheel as the maximum friction coefficient of the wheels.
Optionally, the step of obtaining the maximum friction coefficient of the left wheel according to the stored driving shaft friction coefficient and left slip ratio corresponding to the at least two sampling moments includes:
obtaining a relation line between the friction coefficient of the driving shaft and the left side slip rate according to the stored friction coefficient of the driving shaft and the left side slip rate corresponding to at least two sampling moments;
and obtaining the maximum value of the friction coefficient of the driving shaft corresponding to the value range of the preset slip ratio according to the relation line between the friction coefficient of the driving shaft and the slip ratio of the left side, and setting the maximum value as the maximum friction coefficient of the wheel on the left side.
Optionally, the step of obtaining the maximum friction coefficient of the right wheel according to the stored friction coefficient of the drive shaft and the right slip ratio corresponding to the at least two sampling moments includes:
obtaining a relation line between the friction coefficient of the driving shaft and the right side slip rate according to the stored friction coefficient of the driving shaft and the right side slip rate corresponding to at least two sampling moments;
and obtaining the maximum value of the friction coefficient of the driving shaft corresponding to the value range of the preset slip ratio according to the relation line between the friction coefficient of the driving shaft and the slip ratio on the right side, and setting the maximum value as the maximum friction coefficient of the wheel on the right side.
Optionally, before the step of calculating the driving shaft friction coefficient corresponding to each sampling time according to the vehicle weight, the vehicle wheel radius, the gravitational acceleration and the engine output torque collected at each sampling time, the step of calculating the left-side slip rate and the right-side slip rate corresponding to each sampling time according to the angular velocity of the driving wheel and the angular velocity of the driven wheel collected at the left and right sides at each sampling time respectively further includes:
acquiring a brake signal, a gear shifting state and a vehicle speed according to a preset sampling frequency;
acquiring the vehicle acceleration at each sampling moment according to the vehicle speed acquired at each sampling moment and the vehicle speed acquired at the previous sampling moment corresponding to each sampling moment;
judging whether the vehicle speed at each sampling moment is greater than or equal to a preset vehicle speed threshold, whether the vehicle acceleration is less than or equal to a preset acceleration threshold, whether the output torque of the engine is greater than a preset torque force threshold, whether a brake signal is non-braking and whether a gear shifting state is in a non-gear shifting process;
and if the vehicle speed at each sampling moment is greater than or equal to a preset vehicle speed threshold value, the vehicle acceleration is less than or equal to a preset acceleration threshold value, the engine output torque is greater than a preset torque force threshold value, the brake signal is non-braking, and the gear shifting state is in a non-gear shifting process, the steps of respectively calculating and storing the left side slip rate and the right side slip rate corresponding to each sampling moment according to the angular speeds of the driving wheels and the driven wheels at the left side and the right side collected at each sampling moment, and calculating and storing the driving shaft friction coefficient corresponding to each sampling moment according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque collected at each sampling moment are performed.
To achieve the above object, the present invention further provides a detection terminal, which includes a memory, a processor and a computer program stored on the memory and operable on the processor, wherein the computer program, when executed by the processor, implements the steps of the wheel friction coefficient detection method as described above.
To achieve the above object, the present invention also provides a computer-readable storage medium having stored thereon a computer program which, when being executed by a processor, implements the steps of the wheel friction coefficient detecting method as described above.
According to the wheel friction coefficient detection method, the detection terminal and the computer readable storage medium, the vehicle weight, the wheel radius and the gravity acceleration are obtained; acquiring the output torque of an engine, the angular speeds of driving wheels on the left side and the right side and the angular speeds of driven wheels according to a preset sampling frequency; respectively calculating and storing a left side slip rate and a right side slip rate corresponding to each sampling moment according to the angular velocity of the driving wheel and the angular velocity of the driven wheel on the left side and the right side acquired at each sampling moment, and calculating and storing a driving shaft friction coefficient corresponding to each sampling moment according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque acquired at each sampling moment; and obtaining the maximum friction coefficient of the wheel according to the stored driving shaft friction coefficient, the left side slip rate and the right side slip rate corresponding to at least two sampling moments. Therefore, the maximum friction coefficient of the wheel can be detected only by the wheel angular speed detection device and the engine torque sensor which are originally arranged according to the vehicle, the gradient of the ramp can be obtained without additionally arranging a gradient sensor, and the manufacturing cost of the vehicle is reduced.
Drawings
FIG. 1 is a schematic diagram of a hardware operating environment according to an embodiment of the present invention;
FIG. 2 is a schematic flow chart illustrating a method for detecting a friction coefficient of a wheel according to a first embodiment of the present invention;
FIG. 3 is a schematic flow chart illustrating a method for detecting a friction coefficient of a wheel according to a second embodiment of the present invention;
fig. 4 is a flowchart illustrating a method for detecting a friction coefficient of a wheel according to a third embodiment of the present invention.
The implementation, functional features and advantages of the objects of the present invention will be further described with reference to the accompanying drawings.
Detailed Description
It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Referring to fig. 1, fig. 1 is a schematic diagram of a hardware structure of a detection terminal provided in various embodiments of the present invention. The detection terminal comprises a communication module 01, a memory 02, a processor 03 and the like. Those skilled in the art will appreciate that the test terminal shown in FIG. 1 may also include more or fewer components than shown, or combine certain components, or a different arrangement of components. The processor 03 is connected to the memory 02 and the communication module 01, respectively, and the memory 02 stores a computer program, which is executed by the processor 03 at the same time.
The communication module 01 may be connected to an external device through a network. The communication module 01 may receive data sent by an external device, and may also send data, instructions, and information to the external device, where the external device may be an electronic device such as a mobile phone, a tablet computer, a notebook computer, and a desktop computer.
The memory 02 may be used to store software programs and various data. The memory 02 may mainly include a program storage area and a data storage area, where the program storage area may store an operating system, an application program required by at least one function (acquiring angular velocities of a driving wheel and a driven wheel on left and right sides according to a preset sampling frequency), and the like; the storage data area may store data or information created according to the use of the sensing terminal, or the like. Further, the memory 02 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device.
The processor 03, which is a control center of the monitoring terminal, connects various parts of the entire monitoring terminal by using various interfaces and lines, and performs various functions of the monitoring terminal and processes data by running or executing software programs and/or modules stored in the memory 02 and calling data stored in the memory 02, thereby performing overall monitoring of the monitoring terminal. Processor 03 may include one or more processing units; preferably, the processor 03 may integrate an application processor, which mainly handles operating systems, user interfaces, application programs, etc., and a modem processor, which mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into the processor 03.
Although not shown in fig. 1, the detection terminal may further include a circuit control module, where the circuit control module is used for being connected to a mains supply to implement power control and ensure normal operation of other components.
Those skilled in the art will appreciate that the configuration of the test terminals shown in FIG. 1 is not intended to be limiting of the test terminals and may include more or fewer components than shown, or some components in combination, or a different arrangement of components.
Various embodiments of the method of the present invention are presented in terms of the above-described hardware architecture.
Referring to fig. 2, in a first embodiment of the wheel friction coefficient detecting method of the present invention, the wheel friction coefficient detecting method includes the steps of:
step S10, acquiring the vehicle weight, the wheel radius and the gravity acceleration;
in the scheme, the gravity acceleration, the vehicle weight and the wheel radius can be stored in a memory of a detection terminal of the vehicle in advance, and when the detection terminal detects a ramp, three parameters of the vehicle weight, the wheel radius and the gravity acceleration can be directly obtained from the memory. The vehicle weight may be the sum of the original weight of the vehicle and the current vehicle load.
Step S20, acquiring the output torque of the engine, the angular speeds of the driving wheels and the driven wheels on the left and right sides according to a preset sampling frequency;
the vehicle comprises a driving wheel and a driven wheel, wherein the driving wheel and the driven wheel are arranged on the same side, namely the driving wheel and the driven wheel are arranged on the left side of the vehicle, and the driving wheel and the driven wheel are arranged on the right side of the vehicle. The vehicle detection terminal is linked with angular speed detection devices of four wheels on the left side and the right side and an engine torque sensor through a vehicle CAN line, then the angular speeds of a driving wheel and a driven wheel on the left side and the right side are respectively collected through the angular speed detection devices of the four wheels on the left side and the right side which are arranged in the vehicle according to a preset sampling frequency, the output torque of the engine is collected through the engine torque sensor, the sampling frequency is up to the sampling frequency within each second, in the scheme, the sampling frequency CAN be 10Hz, namely sampling is performed once every 100ms, or 20Hz, namely sampling is performed once every 50ms, and the sampling frequency is not limited.
Step S30, respectively calculating and storing a left side slip rate and a right side slip rate corresponding to each sampling time according to the angular velocity of the driving wheel and the angular velocity of the driven wheel on the left side and the right side acquired at each sampling time, and calculating and storing a driving shaft friction coefficient corresponding to each sampling time according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque acquired at each sampling time;
at each sampling moment, the detection terminal respectively calculates the left side slip rate and the right side slip rate corresponding to each sampling moment according to the angular speeds of the driving wheel and the driven wheel on the left side and the right side collected at each sampling moment, and calculates the driving shaft friction coefficient corresponding to each sampling moment according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque collected at each sampling moment. And after the driving shaft friction coefficient, the left slip rate and the right slip rate corresponding to the sampling moment are calculated and obtained by the detection terminal, the obtained driving friction coefficient, the left slip rate and the right slip rate are stored in a memory.
And step S40, obtaining the maximum friction coefficient of the wheel according to the drive shaft friction coefficient, the left side slip ratio and the right side slip ratio corresponding to at least two stored sampling moments.
After the driving shaft friction coefficients corresponding to at least two checking moments are stored in the memory of the current detection terminal, the driving shaft friction coefficients, the left side slip rate and the right side slip rate corresponding to at least two stored adopting moments are obtained from the memory, and then the maximum friction coefficient of the wheel is obtained by the detection terminal according to the driving shaft friction coefficients, the left side slip rate and the right side slip rate corresponding to at least two stored sampling moments.
Specifically, step S40 includes:
step S41, obtaining the maximum friction coefficient of the left wheel according to the stored drive shaft friction coefficient and left slip ratio corresponding to at least two sampling moments;
and the detection terminal takes the friction coefficient of the driving shaft as a vertical coordinate and the left side slip rate as a horizontal coordinate, and then performs relation line fitting of the friction coefficient and the slip rate of the driving shaft according to the stored friction coefficient of the driving shaft and the left side slip rate corresponding to at least two sampling moments to obtain a relation line between the friction coefficient of the driving shaft and the left side slip rate. And then obtaining the maximum value of the friction coefficient of the driving shaft on the relation line between the friction coefficient of the driving shaft and the left side slip rate when the left side slip rate is in a preset slip value range through the relation line between the friction coefficient of the driving shaft and the left side slip rate, and taking the maximum value as the maximum friction coefficient of the left side wheel. For example, the detection terminal obtains the driving shaft friction coefficient and the left side slip ratio corresponding to three sampling moments, and then performs the fitting of the relation line between the driving shaft friction coefficient and the left side slip ratio, so as to obtain the fitting function of the relation line as follows:
wherein b is1、c1And d1Parameters of a fitting function of a relation line between the friction coefficient of the drive shaft and the slip ratio on the left side, and finally S is obtained according to the fitting function of the relation lineLeft side ofIs located at [0, 1]When the value is within the range, ULeft side ofMaximum value of ULeft maxThe detection terminal will send the ULeft maxAs the left wheel maximum coefficient of friction.
Step S42, obtaining the maximum friction coefficient of the right wheel according to the stored friction coefficients of the driving shaft and the right slip ratio corresponding to at least two sampling moments;
and the detection terminal takes the friction coefficient of the driving shaft as a vertical coordinate and the right-side slip rate as a horizontal coordinate, and then performs the fitting of the relation line between the friction coefficient of the driving shaft and the right-side slip rate according to the stored friction coefficient of the driving shaft and the right-side slip rate corresponding to at least two sampling moments to obtain the relation line between the friction coefficient of the driving shaft and the right-side slip rate. And then obtaining the maximum driving shaft friction coefficient on the relation line between the driving shaft friction coefficient and the right side slip ratio when the right side slip ratio is in the preset slip value range, and taking the maximum driving shaft friction coefficient as the maximum friction coefficient of the right side wheel. For example, the detection terminal obtains the driving shaft friction coefficient and the right slip ratio corresponding to three sampling moments, and then performs fitting on a relation line between the driving shaft friction coefficient and the right slip ratio, wherein the fitting function of the relation line is obtained as follows:
wherein b is2、c2And d2Parameters of a fitting function of a relation line between the friction coefficient of the drive shaft and the right slip ratio, and finally S is obtained according to the fitting function of the relation lineRight sideIs located at [0, 1]When in the value range of (1), URight sideMaximum value of URight maxThe detection terminal will send the URight maxAs the maximum friction coefficient of the right wheel.
Step S43, judging whether the difference value between the maximum friction coefficient of the left wheel and the maximum friction coefficient of the right wheel is smaller than a preset threshold value; if yes, go to step S44;
in step S44, the average of the maximum friction coefficient of the left wheel and the maximum friction coefficient of the right wheel is taken as the maximum friction coefficient of the wheel.
After the detection terminal obtains the maximum friction coefficient of the left wheel and the maximum friction coefficient of the right wheel, whether the difference value between the maximum friction coefficient of the left wheel and the maximum friction coefficient of the right wheel is smaller than a preset threshold value or not is judged, and if the difference value is within the preset threshold value range, the average value of the maximum friction coefficient of the left wheel and the maximum friction coefficient of the right wheel is used as the maximum friction coefficient of the wheel by the detection terminal.
It should be noted that the timing of executing the step S41-step S42 by the detecting terminal may be before executing the step S43-step S44, or after executing the step S43-step S44, or may be simultaneously executing the step S41-step S42 and the step S43-step S44.
It should be noted that, after the detection terminal collects the wheel angular velocity and the engine output torque once according to the preset sampling frequency, the detection terminal respectively calculates and stores the left-side slip rate and the right-side slip rate corresponding to the sampling time according to the collected angular velocities of the driving wheel and the driven wheel on the left and right sides, and calculates and stores the drive shaft friction coefficient corresponding to each sampling time according to the vehicle weight, the wheel radius, the gravitational acceleration and the engine output torque collected at the sampling time. When the detection terminal stores the left-side slip rate, the right-side slip rate and the driving shaft friction coefficient corresponding to one sampling time every time, the driving shaft friction coefficients and the left-side slip rates corresponding to at least two latest stored sampling times are selected from the left-side slip rate, the right-side slip rate and the driving shaft friction coefficient corresponding to each sampling time stored in the storage, and the latest maximum friction coefficient of the vehicle wheel is obtained according to the driving shaft friction coefficients and the left-side slip rates corresponding to at least two latest stored sampling times. So that the detected maximum friction coefficient of the wheel can be updated in real time.
In the embodiment, the vehicle weight, the wheel radius and the gravity acceleration are obtained; acquiring the output torque of an engine, the angular speeds of driving wheels and driven wheels on the left side and the right side of the engine according to a preset sampling frequency; respectively calculating and storing a left side slip rate and a right side slip rate corresponding to each sampling moment according to the angular speed of the driving wheel and the angular speed of the driven wheel on the left side and the right side acquired at each sampling moment, and calculating and storing a driving shaft friction coefficient corresponding to each sampling moment according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque acquired at each sampling moment; and obtaining the maximum friction coefficient of the wheel according to the stored friction coefficient of the driving shaft, the left side slip ratio and the right side slip ratio corresponding to the at least two sampling moments. Therefore, the maximum friction coefficient of the wheel can be detected only according to the wheel angular speed detection device and the engine torque sensor which are originally arranged on the vehicle, the gradient of the ramp can be obtained without additionally arranging a gradient sensor, and the manufacturing cost of the vehicle is reduced.
Further, referring to fig. 3, fig. 3 is a second embodiment of the method for detecting a friction coefficient of a wheel according to the present application, wherein the step S30 includes:
step S31, respectively calculating a left side slip rate and a right side slip rate corresponding to each sampling time according to the angular velocity of the driving wheel and the angular velocity of the driven wheel on the left side and the right side acquired at each sampling time, and calculating a driving shaft friction coefficient corresponding to each sampling time according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque acquired at each sampling time;
at each sampling moment, the detection terminal respectively calculates the left side slip rate and the right side slip rate corresponding to each sampling moment according to the angular speeds of the driving wheel and the driven wheel on the left side and the right side collected at each sampling moment, and calculates the driving shaft friction coefficient corresponding to each sampling moment according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque collected at each sampling moment.
Specifically, step S31 includes:
step S311, calculating a left side slip rate corresponding to each sampling time according to a preset left side slip rate calculation formula, the left side driving wheel angular velocity and the left side driven wheel angular velocity acquired at each sampling time, where the preset left side slip rate calculation formula is:
Sleft side of＝(vLeft slave-vLeft main)/vLeft mainWherein v isLeft slaveLeft-hand driven wheel angular velocity, v, acquired for each sampling instantLeft mainLeft active wheel angular velocity, S, collected for each sampling instantLeft side ofThe left side slip rate corresponding to each sampling time is obtained;
and at each sampling moment, the detection terminal inputs the angular speed of the driving wheel and the angular speed of the driven wheel on the left side of the vehicle, which are acquired at the sampling moment, into a preset slip rate calculation formula, and the left side slip rate corresponding to each sampling moment is calculated and obtained.
Step S312, calculating a right side slip rate corresponding to each sampling time according to a preset right side slip rate calculation formula, and the right side driving wheel angular velocity and the driven wheel angular velocity input acquired at each sampling time, wherein the preset right side slip rate calculation formula is as follows:
Sright side＝(vRight slave-vRight main)/vRight mainWherein v isRight slaveThe angular velocity, v, of the driven wheel on the right acquired for each sampling instantRight mainThe right-hand active wheel angular velocity, S, collected for each sampling instantRight sideThe right slip rate corresponding to each sampling time is obtained;
and at each sampling moment, the detection terminal inputs the angular speed of the driving wheel and the angular speed of the driven wheel on the right side of the vehicle, which are acquired at the sampling moment, into a preset slip rate calculation formula, and the right side slip rate corresponding to each sampling moment is calculated and obtained.
Step S313, according to a preset driving shaft friction coefficient calculation formula, the vehicle weight, the wheel radius and the engine output torque acquired at each sampling moment, calculating a driving shaft friction coefficient corresponding to each sampling moment, wherein the preset driving shaft friction coefficient calculation formula is as follows:
and u is T/(r m g), wherein T is the output torque of the engine collected by the current sampling, r is the radius of the wheel, m is the weight of the vehicle body, g is the gravity acceleration, and u is the friction coefficient of the driving shaft corresponding to each sampling moment.
And at each sampling moment, the detection terminal inputs the obtained vehicle weight, the wheel radius and the engine output torque collected at the sampling moment into a preset driving shaft friction coefficient calculation formula, and calculates and obtains a driving shaft friction coefficient corresponding to each sampling moment.
The execution sequence among step S311, step S312, and step S313 is not limited in this embodiment.
Step S32, respectively judging whether the left side slip ratio and the right side slip ratio corresponding to each sampling time are in a preset slip ratio range and whether the driving shaft friction coefficient corresponding to each sampling time is in a preset friction coefficient range;
step S33, if the driving shaft friction coefficient corresponding to the sampling time is within the preset friction coefficient range and the left-side slip rate and the right-side slip rate corresponding to the sampling time are both within the preset slip rate range, storing the driving shaft friction coefficient, the left-side slip rate and the right-side slip rate corresponding to the sampling time.
Every time sampling is performed, the detection terminal calculates the left-side slip rate, the right-side slip rate and the driving shaft friction coefficient corresponding to the sampling time, and judges the validity of the values of the left-side slip rate, the right-side slip rate and the driving shaft friction coefficient obtained by calculation at the sampling time, specifically, judges whether the left-side slip rate and the right-side slip rate corresponding to the sampling time are within a preset slip rate range, for example, the preset slip rate range is [ -0.05, 0.2], and whether the driving shaft friction coefficient corresponding to the sampling time is within a preset friction coefficient range, for example, the preset friction coefficient range is [ -0.05, 0.6 ]. If the driving shaft friction coefficient corresponding to the sampling moment is in the preset friction coefficient range and the left side slip rate and the right side slip rate corresponding to each sampling moment are in the preset slip rate range, the detection terminal stores the driving shaft friction coefficient, the left side slip rate and the right side slip rate corresponding to the sampling moment, otherwise, as long as at least one of the left side slip rate, the right side slip rate and the driving shaft friction coefficient corresponding to the sampling moment is not in the corresponding preset range, the detection terminal discards the driving shaft friction coefficient, the left side slip rate and the right side slip rate calculated at the sampling moment, and continues to collect the engine output torque, the driving wheel angular speeds on the left side and the right side and the angular speeds of the driven wheels at the next sampling moment according to the preset sampling frequency.
In the embodiment, whether the driving shaft friction coefficient, the left-side slip rate and the right-side slip rate calculated at each sampling moment are in the effective range is judged, so that whether the calculated driving shaft friction coefficient, the calculated left-side slip rate and the calculated right-side slip rate are stored or not is determined and is used as a basis for subsequently obtaining the maximum friction coefficient of the wheel, and the accuracy of the finally obtained maximum friction coefficient of the wheel is improved.
Further, referring to fig. 4, fig. 4 is a third embodiment of the method for detecting a friction coefficient of a wheel according to the present application, according to the first embodiment and the second embodiment of the method for detecting a friction coefficient of a wheel according to the present application, and in the present embodiment, the step S30 includes:
step S50, acquiring a brake signal, a gear shifting state and a vehicle speed in real time according to a preset sampling frequency;
step S60, obtaining the vehicle acceleration at each sampling time according to the vehicle speed collected at each sampling time and the vehicle speed collected at the previous sampling time corresponding to each sampling time;
step S70, judging whether the vehicle speed at each sampling moment is greater than or equal to a preset vehicle speed threshold value, whether the vehicle acceleration is less than or equal to a preset acceleration threshold value, whether the output torque of the engine is greater than a preset torque force threshold value, whether the brake signal is in a non-braking state and whether the gear shifting state is in a non-gear shifting process; if the vehicle speed at each sampling moment is greater than or equal to the preset vehicle speed threshold, the vehicle acceleration is less than or equal to the preset acceleration threshold, the engine output torque is greater than the preset torque force threshold, the brake signal is non-braking, and the gear shifting state is in the non-gear shifting process, step S30 is executed.
In this embodiment, the detection terminal collects the angular velocity of the driving wheel, the angular velocity of the driven wheel and the output torque of the engine on the left and right sides, and also collects the vehicle speed, the brake signal and the gear shifting state according to the preset sampling frequency. Therefore, before the step of executing the step of respectively calculating and storing the left side slip rate and the right side slip rate corresponding to each sampling moment according to the angular speeds of the driving wheels and the driven wheels on the left side and the right side acquired at each sampling moment by the detection terminal, calculating and storing the driving shaft friction coefficient corresponding to each sampling moment according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque acquired at each sampling moment, the detection terminal obtains the vehicle acceleration at the sampling moment according to the vehicle speed at the sampling moment and the vehicle speed at the previous sampling moment corresponding to the sampling moment according to the preset sampling frequency, and then continuously judges whether the vehicle speed at the sampling moment is greater than or equal to the preset vehicle speed threshold value which can be 10km/h, and whether the vehicle acceleration at the sampling moment is less than or equal to the preset acceleration threshold value, the preset acceleration threshold value can be 1.56m/s, whether the output torque of the engine at the sampling moment is larger than a preset torque threshold value or not, the preset torque threshold value is 0, whether the brake signal at the sampling moment is non-braking or not, and whether the gear shifting state at the sampling moment is in a non-gear shifting process or not; only if the vehicle speed at the sampling moment is greater than or equal to a preset vehicle speed threshold value, the vehicle acceleration at the sampling moment is less than or equal to a preset acceleration threshold value, the engine output torque at the sampling moment is greater than a preset torque threshold value, the brake signal at the sampling moment is non-braking, and the gear shifting state at the sampling moment is in a non-gear shifting process, the detection terminal can confirm that the current driving state of the vehicle is suitable for calculating the slip rate and the friction coefficient of the driving shaft, respectively calculate the left slip rate and the right slip rate corresponding to the sampling moment according to the angular speeds of the driving wheels and the driven wheels on the left side and the right side collected at the sampling moment, and calculate the friction coefficient of the driving shaft corresponding to the sampling moment in real time according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque collected at the sampling moment. If any of the 5 determination conditions is not in accordance with the preset condition, for example, the vehicle speed at the sampling time is less than the preset vehicle speed threshold, or the vehicle acceleration at the sampling time is greater than the preset acceleration threshold, or the engine output torque at the sampling time is less than the preset torque threshold, or the brake signal at the current sampling time is not non-braking and is in the braking process, or the gear shifting state at the current sampling time is not in the non-gear shifting process and is in the gear shifting process, the detection terminal may determine that the current vehicle driving state is not suitable for performing the slip rate and the driving shaft friction coefficient calculation, which may affect the accuracy of the final wheel maximum friction calculation, and may not calculate the left side slip rate and the right side slip rate corresponding to the sampling time according to the angular velocities of the driving wheel and the driven wheel at the left side and the right side acquired at the sampling time, and in real time according to, And calculating the friction coefficient of a driving shaft corresponding to the sampling moment according to the wheel radius, the gravity acceleration and the engine output torque acquired at the sampling moment, and continuously acquiring the angular speed of a driving wheel, the angular speed of a driven wheel, the vehicle speed, the engine output torque, a brake signal and a gear shifting state at the left side and the right side at the next sampling moment according to a preset sampling frequency.
In the embodiment, before the slip ratio and the friction coefficient of the driving shaft are calculated, whether the current running state of the vehicle influences the calculation results of the slip ratio and the friction coefficient of the driving shaft is judged according to the vehicle speed, the vehicle acceleration, the engine output torque, the brake signal and the gear shifting state, so that the calculation result of the maximum friction coefficient of the wheel which is inaccurate is avoided.
The invention also proposes a computer-readable storage medium on which a computer program is stored. The computer-readable storage medium may be the Memory 02 in the detection terminal of fig. 1, and may also be at least one of a ROM (Read-Only Memory)/RAM (Random Access Memory), a magnetic disk, and an optical disk, and the computer-readable storage medium includes several pieces of information for enabling the detection terminal to execute the method according to the embodiments of the present invention.
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 an … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.
The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.
Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better embodiment.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the present specification and drawings, or used directly or indirectly in other related fields, are included in the scope of the present invention.
Claims (10)
1. A wheel friction coefficient detection method is characterized by comprising the following steps:
acquiring the vehicle weight, the wheel radius and the gravity acceleration;
acquiring the output torque of an engine, the angular speeds of driving wheels and driven wheels on the left side and the right side of the engine according to a preset sampling frequency;
respectively calculating and storing a left side slip rate and a right side slip rate corresponding to each sampling moment according to the angular velocity of the driving wheel and the angular velocity of the driven wheel on the left side and the right side acquired at each sampling moment, and calculating and storing a driving shaft friction coefficient corresponding to each sampling moment according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque acquired at each sampling moment;
and obtaining the maximum friction coefficient of the wheel according to the stored driving shaft friction coefficient, the left side slip rate and the right side slip rate corresponding to at least two sampling moments.
2. The wheel friction coefficient detection method according to claim 1, wherein the step of calculating and storing a left-side slip rate and a right-side slip rate corresponding to each sampling time, respectively, based on the angular velocities of the driving wheel and the driven wheel on the left and right sides acquired at each sampling time, and the step of calculating and storing a drive shaft friction coefficient corresponding to each sampling time, based on the vehicle weight, the wheel radius, the gravitational acceleration, and the engine output torque acquired at each sampling time, comprises:
respectively calculating a left side slip rate and a right side slip rate corresponding to each sampling moment according to the angular speeds of the driving wheel and the driven wheel on the left side and the right side acquired at each sampling moment, and calculating a driving shaft friction coefficient corresponding to each sampling moment according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque acquired at each sampling moment;
respectively judging whether the left side slip rate and the right side slip rate corresponding to each sampling moment are in a preset slip rate range and whether the driving shaft friction coefficient corresponding to each sampling moment is in a preset friction coefficient range;
and if the driving shaft friction coefficient corresponding to the sampling moment is in the preset friction coefficient range and the left side slip rate and the right side slip rate corresponding to the sampling moment are both in the preset slip rate range, storing the driving shaft friction coefficient, the left side slip rate and the right side slip rate corresponding to the sampling moment.
3. The wheel friction coefficient detection method according to claim 2, wherein the step of calculating the left-side slip rate and the right-side slip rate corresponding to each sampling time, respectively, based on the angular velocities of the driving wheel and the driven wheel on the left and right sides acquired at each sampling time, includes:
calculating a left side slip rate corresponding to each sampling moment according to a preset left side slip rate calculation formula, the left side driving wheel angular speed and the left side driven wheel angular speed acquired at each sampling moment, wherein the preset left side slip rate calculation formula is as follows:
Sleft side of＝(vLeft slave-vLeft main)/vLeft mainWherein v isLeft slaveLeft-hand driven wheel angular velocity, v, acquired for each sampling instantLeft mainLeft active wheel angular velocity, S, collected for each sampling instantLeft side ofThe left side slip rate corresponding to each sampling moment;
according to a preset right side slip rate calculation formula, and input of the angular speed of the driving wheel and the angular speed of the driven wheel on the right side acquired at each sampling moment, calculating the right side slip rate corresponding to each sampling moment, wherein the preset right side slip rate calculation formula is as follows:
Sright side＝(vRight slave-vRight main)/vRight mainWherein v isRight slaveThe angular velocity, v, of the driven wheel on the right acquired for each sampling instantRight mainThe right-hand active wheel angular velocity, S, collected for each sampling instantRight sideThe right slip rate for each sampling instant.
4. The wheel friction coefficient detection method according to claim 2, wherein the step of calculating the drive shaft friction coefficient corresponding to each sampling timing based on the vehicle weight, the wheel radius, the gravitational acceleration, and the engine output torque acquired at each sampling timing includes:
calculating a driving shaft friction coefficient corresponding to each sampling moment according to a preset driving shaft friction coefficient calculation formula, the vehicle weight, the wheel radius and the engine output torque acquired at each sampling moment, wherein the preset driving shaft friction coefficient calculation formula is as follows:
and u is T/(r m g), wherein T is the engine output torque collected at each sampling moment, r is the radius of the wheel, m is the weight of the vehicle body, g is the gravity acceleration, and u is the friction coefficient of the driving shaft corresponding to each sampling moment.
5. The wheel friction coefficient detection method according to any one of claims 1 to 4, wherein the step of obtaining the maximum friction coefficient of the wheel from the drive shaft friction coefficient, the left-side slip ratio, and the right-side slip ratio corresponding to the stored at least two sampling times includes:
obtaining the maximum friction coefficient of the left wheel according to the stored drive shaft friction coefficients and left slip rates corresponding to at least two sampling moments;
obtaining the maximum friction coefficient of the right wheel according to the stored driving shaft friction coefficient and the right slip ratio corresponding to at least two sampling moments;
judging whether the difference value between the maximum friction coefficient of the left wheel and the maximum friction coefficient of the right wheel is smaller than a preset threshold value or not;
if so, the average value of the maximum friction coefficient of the left wheel and the maximum friction coefficient of the right wheel is taken as the maximum friction coefficient of the wheel.
6. The method for detecting a friction coefficient of a wheel according to claim 5, wherein the step of obtaining the maximum friction coefficient of the left wheel based on the stored friction coefficients of the drive shaft and the left slip ratio corresponding to the at least two sampling times comprises:
obtaining a relation line between the friction coefficient of the driving shaft and the left side slip rate according to the stored friction coefficient of the driving shaft and the left side slip rate corresponding to at least two sampling moments;
and obtaining the maximum value of the friction coefficient of the driving shaft corresponding to the value range of the preset slip ratio according to the relation line between the friction coefficient of the driving shaft and the slip ratio of the left side, and setting the maximum value as the maximum friction coefficient of the wheel on the left side.
7. The wheel friction coefficient detection method according to claim 5, wherein the step of obtaining the maximum friction coefficient of the right wheel based on the stored drive shaft friction coefficient and the right slip ratio corresponding to the at least two sampling times comprises:
obtaining a relation line between the friction coefficient of the driving shaft and the right side slip rate according to the stored friction coefficient of the driving shaft and the right side slip rate corresponding to at least two sampling moments;
and obtaining the maximum value of the friction coefficient of the driving shaft corresponding to the value range of the preset slip ratio according to the relation line between the friction coefficient of the driving shaft and the slip ratio on the right side, and setting the maximum value as the maximum friction coefficient of the wheel on the right side.
8. The method for detecting the friction coefficient of a wheel according to claim 5, wherein the step of calculating the left-side slip rate and the right-side slip rate corresponding to each sampling time according to the angular velocities of the driving wheel and the driven wheel on the left and right sides acquired at each sampling time, respectively, and the step of calculating the friction coefficient of the driving shaft corresponding to each sampling time according to the vehicle weight, the wheel radius, the gravitational acceleration and the engine output torque acquired at each sampling time in real time further comprises:
acquiring a brake signal, a gear shifting state and a vehicle speed according to a preset sampling frequency;
acquiring the vehicle acceleration at each sampling moment according to the vehicle speed acquired at each sampling moment and the vehicle speed acquired at the previous sampling moment corresponding to each sampling moment;
judging whether the vehicle speed at each sampling moment is greater than or equal to a preset vehicle speed threshold, whether the vehicle acceleration is less than or equal to a preset acceleration threshold, whether the output torque of the engine is greater than a preset torque force threshold, whether a brake signal is non-braking and whether a gear shifting state is in a non-gear shifting process;
and if the vehicle speed at each sampling moment is greater than or equal to a preset vehicle speed threshold value, the vehicle acceleration is less than or equal to a preset acceleration threshold value, the engine output torque is greater than a preset torque force threshold value, the brake signal is non-braking, and the gear shifting state is in a non-gear shifting process, respectively calculating and storing a left side slip rate and a right side slip rate corresponding to each sampling moment according to the angular speeds of the driving wheels and the driven wheels at the left side and the right side acquired at each sampling moment, and calculating and storing a driving shaft friction coefficient corresponding to each sampling moment according to the vehicle weight, the wheel radius, the gravity acceleration and the engine output torque acquired at each sampling moment.
9. A detection terminal, characterized in that it comprises a memory, a processor and a computer program stored on said memory and executable on said processor, said computer program, when executed by said processor, implementing the steps of the wheel friction coefficient detection method according to any one of claims 1 to 8.
10. A computer-readable storage medium, characterized in that a computer program is stored thereon, which computer program, when being executed by a processor, carries out the steps of the wheel friction coefficient detection method according to one of claims 1 to 8.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH063257A (en) * | 1992-06-24 | 1994-01-11 | Honda Motor Co Ltd | Surface friction coefficient arithmetic device |
| CN101109695A (en) * | 2007-09-05 | 2008-01-23 | 张启明 | Continuous pavement friction coefficient testing method |
| CN101581659A (en) * | 2009-06-05 | 2009-11-18 | 清华大学 | Tyre-pavement maximum attachment coefficient test method |
| US20100211256A1 (en) * | 2009-02-16 | 2010-08-19 | Honda Motor Co., Ltd. | Road surface frictional coefficient estimating apparatus |
| CN101825510A (en) * | 2010-05-17 | 2010-09-08 | 北京航空航天大学 | Method for estimating brake pressure of automobile and peak value of road adhesion coefficient |
| CN103612634A (en) * | 2013-12-03 | 2014-03-05 | 北京交通大学 | Method for estimating road adhesion coefficient of electromobile driven by distributed hub motor |
| CN107664551A (en) * | 2017-06-19 | 2018-02-06 | 河海大学 | A kind of real-time computing technique of vehicle and road surface friction force |
| CN107685733A (en) * | 2017-08-14 | 2018-02-13 | 哈尔滨工业大学 | The method of estimation of four motorized wheels electric automobile coefficient of road adhesion |
| US20200023852A1 (en) * | 2017-02-06 | 2020-01-23 | Seoul National University R&Db Foundation | Method for estimating road surface friction coefficient of tire and device for estimating road surface friction coefficient of tire in high speed normal driving state |
-
2020
- 2020-06-30 CN CN202010609123.0A patent/CN112113779B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH063257A (en) * | 1992-06-24 | 1994-01-11 | Honda Motor Co Ltd | Surface friction coefficient arithmetic device |
| CN101109695A (en) * | 2007-09-05 | 2008-01-23 | 张启明 | Continuous pavement friction coefficient testing method |
| US20100211256A1 (en) * | 2009-02-16 | 2010-08-19 | Honda Motor Co., Ltd. | Road surface frictional coefficient estimating apparatus |
| CN101581659A (en) * | 2009-06-05 | 2009-11-18 | 清华大学 | Tyre-pavement maximum attachment coefficient test method |
| CN101825510A (en) * | 2010-05-17 | 2010-09-08 | 北京航空航天大学 | Method for estimating brake pressure of automobile and peak value of road adhesion coefficient |
| CN103612634A (en) * | 2013-12-03 | 2014-03-05 | 北京交通大学 | Method for estimating road adhesion coefficient of electromobile driven by distributed hub motor |
| US20200023852A1 (en) * | 2017-02-06 | 2020-01-23 | Seoul National University R&Db Foundation | Method for estimating road surface friction coefficient of tire and device for estimating road surface friction coefficient of tire in high speed normal driving state |
| CN107664551A (en) * | 2017-06-19 | 2018-02-06 | 河海大学 | A kind of real-time computing technique of vehicle and road surface friction force |
| CN107685733A (en) * | 2017-08-14 | 2018-02-13 | 哈尔滨工业大学 | The method of estimation of four motorized wheels electric automobile coefficient of road adhesion |
Non-Patent Citations (1)
| Title |
|---|
| 吕俊成等: "微型汽车离合器摩擦材料摩擦磨损性能的研究", 《武汉理工大学学报》 * |
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