The present disclosure relates to the technical field of vehicles, and particularly to a vehicle and a method and apparatus for identifying vehicle load distribution, and a non-transitory computer-readable storage medium and an electronic device.
When measuring the load distribution of the front and rear axles of a vehicle, it is generally necessary to install a load sensor or at least two body height sensors at the suspension. In order to avoid installation of the aforementioned sensors at the suspension, in the related art, it is proposed to indirectly estimate the front and rear load levels according to deformation of the tire under different loads. As shown in
However, this technology needs to identify the resonance spectrum characteristics of the front and rear wheels, which involves a large amount of calculation, and the rear wheels of most of the front-wheel-drive vehicle models lack apparent resonance characteristics (or the apparent resonance characteristics can only be identified in some vehicle speed segments), so the corresponding resonance energy characteristic values cannot be obtained. Therefore, this technology has a rather limited application range.
The present disclosure solves at least one of technical problems in the related art. at a first aspect, the present disclosure provides a method for identifying vehicle load distribution, to reduce the cost of vehicle load distribution identification and extend the application range.
In a second aspect, the present disclosure provides a vehicle load distribution identification apparatus.
In a third aspect, the present disclosure provides a non-transitory computer-readable storage medium.
In a fourth aspect, the present disclosure provides an electronic device.
In a fifth aspect, the present disclosure provides a vehicle.
An embodiment in a first aspect of the present disclosure provides a vehicle load distribution identification method including the steps of: detecting a speed and longitudinal acceleration of the vehicle; acquiring a driving force of the vehicle when the longitudinal acceleration is less than an acceleration threshold; obtaining, by a processor, a pitch angle of the vehicle according to the driving force and the vehicle speed; and obtaining, by the processor, load distribution of the vehicle according to the pitch angle.
According to an embodiment of the present disclosure, the obtaining the pitch angle of the vehicle according to the driving force and the vehicle speed includes: obtaining a reference driving force corresponding to the vehicle speed according to the vehicle speed and acquiring a reference pitch angle; and obtaining the pitch angle according to the driving force, the reference driving force and the reference pitch angle.
According to an embodiment of the present disclosure, the obtaining the pitch angle according to the driving force, the reference driving force and the reference pitch angle includes: calculating a first difference between the reference driving force and the driving force; acquiring the mass of the vehicle and calculating a first ratio of the first difference to the mass; and summing the first ratio with the reference pitch angle to obtain the pitch angle.
According to an embodiment of the present disclosure, the obtaining the pitch angle according to the driving force, the reference driving force and the reference pitch angle includes: calculating an average of a plurality of the driving forces to obtain an average driving force; calculating a second difference between the reference driving force and the average driving force; acquiring the mass of the vehicle and calculating a second ratio of the second difference to the mass; and summing the second ratio with the reference pitch angle to obtain the pitch angle.
According to an embodiment of the present disclosure, the obtaining load distribution of the vehicle according to the pitch angle includes: acquiring a front-rear wheelbase, the stiffness of a front suspension and the stiffness of a rear suspension of the vehicle; and calculating the load distribution of the vehicle according to the pitch angle, the front-rear wheelbase, the stiffness of the front suspension and the stiffness of the rear suspension.
According to an embodiment of the present disclosure, the load distribution of the vehicle is calculated by the following equation:
where θ is the pitch angle, L is the front-rear wheelbase, k1 is the stiffness of the front suspension, k2 is the stiffness of the rear suspension, and F1 is a front axle load, and F2 is a rear axle load of the vehicle.
An embodiment in a second aspect of the present disclosure provides a vehicle load distribution identification apparatus, including: a first acquisition module configured to detect a speed and longitudinal acceleration of the vehicle; a second acquisition module configured to acquire an driving force of the vehicle when the longitudinal acceleration is less than an acceleration threshold; a calculation module configured to obtain an pitch angle of the vehicle according to the driving force and the vehicle speed; and an identification module configured to obtain load distribution of the vehicle according to the pitch angle.
An embodiment in a third aspect of the present disclosure provides a computer-readable storage medium having a computer program stored thereon, where when executed by a processor, the computer program implements the vehicle load distribution identification method described above.
An embodiment in a fourth aspect of the present disclosure provides an electronic device, including a memory and a processor, the memory having a computer program stored thereon. When executed by the processor, the computer program implements the vehicle load distribution identification method described above.
An embodiment in a fifth embodiment of the present disclosure provides a vehicle including the vehicle load distribution identification apparatus according to the embodiment described above or the electronic device according to the embodiment described above.
With the vehicle, the method, the apparatus, the medium, and the electronic device for identifying vehicle load distribution according to the embodiments of the present disclosure, the difference between the front and rear axle loads of the vehicle can be identified by calculating the pitch angle of the vehicle, so that the vehicle load distribution can be identified without installing dedicated sensors such as a load sensor and a vehicle body height sensor at the vehicle suspension, which reduces the cost for identifying vehicle load distribution and allows a wide range of applications to all vehicle models.
Some of additional aspects and advantages of the present disclosure will be given in the following description, and become apparent from the following description, or be learned from practices of the present disclosure.
Embodiments of the present disclosure are described in detail below, and examples of the embodiments are shown in the drawings, where the same or similar elements or the elements having same or similar functions are denoted by the same or similar reference numerals throughout the description. The embodiments described below with reference to the drawings are examples to explain the present disclosure, and shall not be construed as limitation of the present disclosure.
The vehicle and the vehicle load distribution identification method and apparatus and the medium and electronic device according to embodiments of the present disclosure will be described below with reference to
First, the principle of vehicle load distribution identification according to the embodiment of the present disclosure will be explained.
As shown in
In an embodiment, the stiffness of the front suspension k1, the stiffness of the rear suspension k2 and the front-rear wheelbase L of the vehicle are acquired from the vehicle parameters, so the relation between the front-rear axle loads and the pitch angle θ is:
As an example, if the stiffnesses of the front and rear suspensions are approximately equal and assumed as k, the pitch angle θ and the difference between the front and rear axle loads ΔF can be simplified as a direct proportion relation:
Therefore, the difference between the front and rear axle loads can be obtained by estimating the pitch angle.
As the acceleration sensor is not kept horizontal, the longitudinal acceleration as measured by it includes the components of the longitudinal acceleration of the vehicle av and the acceleration of gravity in the measurement direction of the sensor: as=av cos θ+g sin α.
The above equation can be approximated as: as=av+gi+gθ
The longitudinal dynamic equation during the travel of the vehicle is as follows:
F
t
=F
w
+F
f
+mgi+δma
v,
where Ft is the driving force, Fw is the air resistance, Ff is the rolling resistance, m is the mass of the vehicle, g is the acceleration of gravity, i is the slope and δ is the conversion coefficient of rotating mass. At a higher gear (lower speed ratio), the conversion coefficient of rotating mass is close to 1. At this time, the longitudinal dynamic equation of the vehicle is simplified as:
F
t
=F
w
+F
f
+m(av+gi).
Substituting the acceleration as measured by the acceleration sensor into the above equation, we can obtain:
F
t
=F
w
+F
f
+m(as−gθ).
When as=0, we can obtain the following from the equation above:
F
t
=F
w
+F
f
+mgθ.
Because the relation between the rolling resistance Ff and the vehicle speed is weak, and the relation between the air resistance Fw and the vehicle speed is approximately quadratic, and its coefficient (that is, the air resistance coefficient) is only related to the shape of the vehicle, the difference in rolling resistance can be ignored, and it can be considered that the same vehicle with different loads experiences the same resistance Fw+Ff when the vehicle speed is the same or similar. Therefore, the difference in pitch angle of the same vehicle traveling at the same speed in different load conditions can be calculated by the following equation (where Ft,1 is the driving force in load condition 1 when as=0; and Ft,2 is the driving force in load condition 2 when as=0):
Based on the foregoing principle, the present disclosure provides a vehicle load distribution identification method.
It should be noted that before performing this vehicle load distribution identification method, the model of correspondence between the load distribution and the reference driving force F0 and the reference pitch angle θ0 needs to be calibrated. In an embodiment, the reference driving force F0 and the reference pitch angle θ0 can be calibrated when the vehicle is in a state with a known load distribution.
In an embodiment, a time interval can be set, and when the vehicle is controlled to run at various vehicle speeds, the acceleration sensor 10 acquires the longitudinal acceleration at the set time interval. Then, a driving force statistical calculation module 30 (which may be a recursive least square (RLS), Kalman filter, or other filters) calculates the driving force corresponding to the longitudinal acceleration measurement (approximation) less than the acceleration threshold, and the driving force can be obtained by multiplying the torque output by the power source (the driving motor of the vehicle) by the speed ratio of the transmission system; Then it can calculate the average of the driving forces to obtain the reference driving force corresponding to each vehicle speed. In an embodiment, N driving forces can be selected to calculate the average, where N is an integer greater than 1 and may assume a value of 3, 4, 5, etc. The acceleration threshold can be calibrated according to experiments, and the acceleration threshold can be different for different vehicle models.
The reference driving force F0 output by the driving force statistical calculation module 30 can be stored in different units of the storage module 40 divided based on the vehicle speeds according to the current vehicle speed. Meanwhile, the reference pitch angle data θ0 calculated (or directly measured) according to the current load distribution can also be stored in the storage module 40.
As shown in
S31: the speed and longitudinal acceleration of the vehicle are detected and obtained.
In an embodiment, the longitudinal acceleration as of the vehicle can be detected and collected by the acceleration sensor 10 shown in 4, and the vehicle speed can be collected by the vehicle speed sensor, where both the acceleration sensor and the vehicle speed sensor can be installed on the vehicle body. In an embodiment, the vehicle speed can also be calculated based on the wheel speed of the vehicle, and the wheel speed can be collected by the wheel speed sensor installed on the wheel.
S32: When the longitudinal acceleration is less than the acceleration threshold, the driving force of the vehicle is acquired.
As an implementation, referring to
S33: the pitch angle of the vehicle is obtained according to the driving force and the vehicle speed.
As an implementation, the obtaining the pitch angle of the vehicle according to the driving force and the vehicle speed can include: obtaining the corresponding reference driving force according to the vehicle speed and acquiring the reference pitch angle; and obtaining the pitch angle according to the driving force, the reference driving force and the reference pitch angle. The preset value can be calibrated as required.
In this implementation, the obtaining the pitch angle according to the driving force, the reference driving force and the reference pitch angle can include: calculating a difference between the reference driving force and the driving force; acquiring the mass of the vehicle and calculating a ratio of the difference to the mass; and summing the ratio with the reference pitch angle to obtain the pitch angle.
In an embodiment, referring to
where θ0 is the reference pitch angle, which can be obtained from the storage module 40; m is the mass of the vehicle; and g is the acceleration of gravity.
In this implementation, the obtaining the pitch angle according to the driving force, the reference driving force and the reference pitch angle can also include: calculating an average of multiple driving forces to obtain an average driving force; calculating a difference between the reference driving force and the average driving force; acquiring the mass of the vehicle and calculating a ratio of the difference to the mass; and summing the ratio with the reference pitch angle to obtain the pitch angle.
In an embodiment, the average driving force can be calculated within a certain period of time. For example, counting is started when it is determined that the longitudinal acceleration is less than the acceleration threshold, and the longitudinal acceleration is continuously monitored/detected. If all the longitudinal accelerations are less than the acceleration threshold within a preset time, or the proportion of the longitudinal accelerations less than the acceleration threshold is greater than a certain value, the average of all the driving forces obtained within the preset time is calculated to obtain the average driving force. The average driving force can also be calculated by statistically counting the number of the driving forces. For example, every time it is determined that the longitudinal acceleration is less than the acceleration threshold, an driving force is obtained. When the number of the driving forces reaches a preset value, the average of the preset number of driving forces is calculated to obtain the average driving force. Referring to
where θ0 is the reference pitch angle, which can be obtained from the storage module 40; m is the mass of the vehicle; and g is the acceleration of gravity.
S34: the load distribution of the vehicle is obtained according to the pitch angle.
As an implementation, the obtaining the load distribution of the vehicle according to the pitch angle can include: acquiring a front-rear wheelbase, the stiffness of a front suspension and the stiffness of a rear suspension of the vehicle; and calculating the load distribution of the vehicle according to the pitch angle, the front-rear wheelbase, the stiffness of the front suspension and the stiffness of the rear suspension.
In an embodiment, referring to
where θ is the pitch angle, L is the front-rear wheelbase, k1, k2 are respectively the stiffness of the front suspension and the stiffness of the rear suspension, and F1, F2 are respectively the front axle load and the rear axle load of the vehicle.
In an embodiment, the obtained static load distribution of the front and rear axles of the vehicle can be used to improve the performance of the following systems: the Antilock Brake System (ABS), the Electronic Stability Program (ESP), the Traction Control System (TCS), the Electric Brakeforce Distribution (EBD), the active suspension Active Body Control (ABC), Anti Rolling Program (ARP), headlight range control, tire pressure monitoring, and the like.
With the vehicle load distribution identification method according to the embodiment of the present disclosure, the vehicle load is not directly measured, instead, the pitch angle of the vehicle is estimated and then the difference between the front axle and rear axle loads can be calculated according to the statics knowledge. As such, the vehicle load distribution can be identified without installing dedicated sensors such as a load sensor and a vehicle body height sensor at the vehicle suspension, which reduces the cost of vehicle load distribution identification and allows a wide range of applications without being limited by the vehicle model.
As shown in
The first acquisition module 110 is configured to acquire/detect a speed and longitudinal acceleration of the vehicle; the second acquisition module 120 is configured to acquire, through statistical calculation, an driving force of the vehicle when the longitudinal acceleration is less than an acceleration threshold; the calculation module 130 is configured to obtain an pitch angle of the vehicle according to the driving force and vehicle speed; and the identification module 140 is configured to obtain load distribution of the vehicle according to the pitch angle.
As an implementation, the calculation module 130 is configured to: when the number of driving forces acquired by the second acquisition module 120 reaches a preset value, calculate the average of the preset number of driving forces to obtain the average driving force; obtain the corresponding reference driving force according to the vehicle speed and obtain a reference pitch angle; and obtain the pitch angle according to the average driving force, the reference driving force and the reference pitch angle.
The calculation module 130 is configured to, in obtaining the pitch angle according to the average driving force and the reference driving force: calculate a difference between the reference driving force and the average driving force; acquire the mass of the vehicle and calculating a ratio of the difference to the mass; and summing the ratio with the reference pitch angle to obtain the pitch angle.
As an implementation, the identification module 140 is configured to: acquire a front-rear wheelbase, the stiffness of a front suspension and the stiffness of a rear suspension of the vehicle; and calculate the load distribution of the vehicle according to the pitch angle, the front-rear wheelbase, the stiffness of the front suspension and the stiffness of the rear suspension.
In an embodiment, the load distribution of the vehicle can be calculated by the following equation:
where θ is the pitch angle, L is the front-rear wheelbase, k1, k2 are respectively the stiffness of the front suspension and the stiffness of the rear suspension, and F1, F2 are respectively the front axle load and the rear axle load of the vehicle.
It should be noted that, for some implementations of the vehicle load distribution identification apparatus 100 according to the embodiment of the present disclosure, reference may be made to the implementations of the vehicle load distribution identification method of the above embodiment of the present disclosure.
With the vehicle load distribution identification apparatus 100 according to the embodiment of the present disclosure, the vehicle load distribution can be identified without installing dedicated sensors such as a load sensor and a vehicle body height sensor at the vehicle suspension, which reduces the cost of vehicle load distribution identification and allows a wide range of applications without being limited by the vehicle model.
The present disclosure provides a computer-readable storage medium.
In this embodiment, the computer-readable storage medium (e.g., the non-transitory computer-readable storage medium) has a computer program stored thereon, which, when executed by a processor, implements the vehicle load distribution identification method described above.
With the computer-readable storage medium according to the embodiment of the present disclosure, when the computer program stored thereon for the vehicle load distribution identification method described above is executed by a processor, the vehicle load distribution can be identified without installing dedicated sensors such as a load sensor and a vehicle body height sensor at the vehicle suspension, which reduces the cost of vehicle load distribution identification and allows a wide range of applications without being limited by the vehicle model.
In an embodiment, the present disclosure further provides an electronic device.
In this embodiment, as shown in
With the electronic device 200 according to the embodiment of the present disclosure, when the computer program 230 stored in the memory 210 thereof for the vehicle load distribution identification method described above is executed by the processor 220, the vehicle load distribution can be identified without installing dedicated sensors such as a load sensor and a vehicle body height sensor at the vehicle suspension, which reduces the cost of vehicle load distribution identification and allows a wide range of applications without being limited by the vehicle model.
As shown in
As shown in
With the vehicle according to the embodiment described above, by use of the vehicle load distribution identification apparatus 100 or the electronic device 200 described above, it is not necessary to install dedicated sensors such as a load sensor and a vehicle body height sensor at the vehicle suspension, which reduces the cost of vehicle load distribution identification and allows a wide range of applications without being limited by the vehicle model.
It should be noted that the logic and/or steps shown in the flowcharts or described in any other manner herein, for example, a sequenced list that may be considered as executable instructions for implementing logical functions, may be embodied in any computer-readable medium to be used by an instruction execution system, apparatus, or device (for example, a computer-based system, a system including a processor, or another system that can fetch an instruction from the instruction execution system, apparatus, or device and execute the instruction) or to be used in combination with such instruction execution systems, apparatuses, or devices. In this specification, the term “computer-readable medium” may be any apparatus that can contain, store, communicate, propagate, or transmit programs to be used by the instruction execution system, apparatus or device or to be used in combination with such instruction execution systems, apparatuses or devices. More examples (a non-exhaustive list) of the computer-readable medium include: an electrical connection part (electronic device) having one or more wires, a portable computer diskette (magnetic apparatus), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber apparatus, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically by, for example, optically scanning the paper or other media, then editing, interpreting, or processing in other suitable ways if necessary, and then storing it in a computer memory.
It should be understood that, various parts of the present disclosure can be implemented in hardware, software, firmware, or a combination thereof. In the foregoing implementations, multiple steps or methods may be implemented by using software or firmware that are stored in a memory and executed by a proper instruction execution system. For example, if implementation is made in hardware, as in another implementation, implementation may be realized by any one of the following technologies well known in the art or a combination thereof: a discrete logic circuit including a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit including a proper combined logic gate circuit, a programmable gate array (PGA), a field programmable gate array (FPGA), and the like.
In the descriptions of this specification, descriptions of a reference term such as “an embodiment,” “some embodiments,” “an example,” “a specific example,” or “some examples” means that a specific feature, structure, material, or characteristic that is described with reference to the embodiment or the example is included in at least one embodiment or example of the present application. In this specification, expressions of the foregoing terms do not necessarily refer to the same embodiment or example. In addition, the described features, structures, materials, or characteristics may be combined in a proper manner in any one or more of the embodiments or examples.
In the description of the present disclosure, it should be understood that orientation or position relations indicated by the terms such as “center”, “longitudinal”, “transverse”, “length”, “width”, “thickness”, “above”, “below”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “anticlockwise”, “axial direction”, “radial direction”, and “circumferential direction” are based on orientation or position relations shown in the drawings, and are used merely for ease and brevity of illustration and description, rather than indicating or implying that the mentioned apparatus or element must have a particular orientation or must be constructed and operated in a particular orientation. Therefore, such terms should not be construed as limitation of the present disclosure.
In addition, the terms “first” and “second” are used merely for the purpose of description, and shall not be construed as indicating or implying relative importance or implying a quantity of indicated technical features. Therefore, a feature defined by the term “first” or “second” may explicitly indicate or implicitly include at least one of such features. In description of the present disclosure, the term “multiple” means at least two, such as two and three, unless it is specifically defined otherwise.
In the present disclosure, unless otherwise explicitly specified or defined, the terms such as “install”, “joint”, “connect”, and “fix” should be understood in a broad sense. For example, the connection may be a fixed connection, a detachable connection, or an integral connection; or the connection may be a mechanical connection or an electrical connection; or the connection may be a direct connection, an indirect connection through an intermediary medium, or internal communication between two elements or mutual reaction relation between two elements, unless otherwise explicitly specified. A person of ordinary skill in the art may understand the meanings of the foregoing terms in the present disclosure according to contexts.
In the present disclosure, unless otherwise explicitly specified or defined, the first feature being located “above” or “below” the second feature may indicate the first feature is in direct contact with the second feature, or the first feature is in indirect contact with the second feature through an intermediary medium. In addition, the first feature being “above”, “over”, or “on” the second feature may indicate that the first feature is directly above or obliquely above the second feature, or may merely indicate that the horizontal position of the first feature is higher than that of the second feature. The first feature being “below”, “under”, and “beneath” the second feature may indicate that the first feature is right below the second feature or obliquely below the second feature, or may merely indicate that the horizontal position of the first feature is lower than that of the second feature.
Although the embodiments of the present disclosure have been shown and described above, it can be understood that the above embodiments are some of the embodiments and should not be understood as limitation of the present disclosure. A person of ordinary skill in the art can make changes, modifications, replacements, or variations to the above embodiments within the scope of the present disclosure.
Number | Date | Country | Kind |
---|---|---|---|
202110687601.4 | Jun 2021 | CN | national |
This application is a Continuation application of International Patent Application No. PCT/CN2022/096177, filed on May 31, 2022, which is based on and claims priority to and benefits of Chinese Patent Application No. 202110687601.4, filed on Jun. 21, 2021. The entire content of all of the above-referenced applications is incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/CN2022/096177 | May 2022 | US |
Child | 18373164 | US |