Design method and device for steering system of electronic guide rubber-tyred vehicle and medium

Abstract

The invention relates to the technical field of vehicle steering systems, in particular to a design method and device for an electronic guide rubber wheel vehicle steering system and a medium, and the design method comprises the steps that a target function E (L, K) with the length K of the bevel edge of a steering trapezoid and the length L of the short edge of the steering trapezoid as independent variables is constructed; based on the target function E (L, K), obtaining the optimal values (L, K) of the length K of the bevel edge of the steering trapezoid and the length L of the short edge of the steering trapezoid, and designing the steering system of the electronic guiding rubber-tyred vehicle according to the optimal values (L, K) so as to improve the Ackerman correction rate of the steering system of the sub-guiding rubber-tyred vehicle. According to the design method disclosed by the invention, the objective function E (L, K) is constructed, so that the problem of no standard basis is solved, and the optimal steering system parameter is found by finding the minimum value of the function; in a mode of stipulating the value ranges and the step lengths of the length L of the short edge of the steering trapezoid and the length K of the bevel edge of the steering trapezoid, more optimization calculation comparison results are increased, and the possibility of missing better parameter values is also avoided; and the Ackerman correction rate is obviously improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of vehicle steering systems, and in particular to a design method, device and medium for an electronically guided rubber-wheeled vehicle steering system. Background Art

[0002] The electronically guided rubber-tyred vehicle is a new type of rail transit system, and its steering system is quite different from that of traditional rail vehicles. Unlike traditional rail vehicles that rely on the wheel-rail relationship for steering, the electronically guided rubber-tyred vehicle travels on urban roads, and its steering system is similar to that of a car. The steering system of the electronically guided rubber-tyred vehicle is divided into a motor vehicle steering system and a trailer steering system, which differ to a certain extent due to the installation location, system function, and active and passive relationship (the motor vehicle steering system is the active input end of the steering signal, and the trailer steering system is the receiving and executing end of the steering signal).

[0003] When designing the steering system of an electronically guided rubber-wheeled vehicle, the inner wheel angle is first provided, and then the inner wheel angle is calculated using the Ackerman principle and the steering trapezoidal principle, striving to make the results calculated using the two principles closer. Finally, the Ackerman correction rate is calculated, which is required to reach more than 80%. The existing calculation method is to perform verification calculations after giving the initial calculation parameters, and the results meet the requirements. However, there is still room for optimization in the calculation results, and the existing calculation methods cannot be optimized. The existing calculation methods are not targeted at electronically guided rubber-wheeled vehicles, and therefore lack coverage of the technical characteristics of electronically guided rubber-wheeled vehicles.

[0004] The steering system of an electronically guided rubber-wheeled vehicle needs to calculate the wheel angle, steering characteristic curve, and Ackerman correction rate during the design process. The calculation steps of the existing steering system calculation method are as follows: (1) Preliminary selection of vehicle steering system calculation parameters (minimum curve radius, vehicle wheelbase, length of the hypotenuse of the steering trapezoid, length of the long side of the steering trapezoid, length of the short side of the steering trapezoid) and the inner wheel turning angle.

[0005] (2) Based on the selected calculation parameters and the inner wheel angle, the outer wheel angle is calculated using the Ackerman principle.

[0006] (3) Based on the selected calculation parameters and the inner wheel turning angle, the outer wheel turning angle is calculated using the steering trapezoid principle.

[0007] (4) Draw the steering trapezoidal characteristic curves separately and compare the two.

[0008] (5) Calculate the Ackerman correction rate.

[0009] The prior art specifically has the following shortcomings: (1) When selecting calculation parameters, they are only selected based on previous design experience, lacking a range of parameter values ​​to choose from, which may lead to missing out on more optimal calculation parameters.

[0010] (2) In the process of comparing characteristic curves, there is no standard basis or objective function for the degree of proximity.

[0011] (3) The calculated Ackerman correction rate cannot be further optimized and remains at around 80%.

[0012] The main reason for the shortcomings of the existing calculation method is that when selecting the calculation parameters, the values ​​of each parameter are fixed. During the calculation process, only a set of comparison results of the steering characteristic curve can be obtained, and there is no more reference information for optimization, resulting in the calculated Ackerman correction rate is not high and cannot be further optimized.

[0013] Therefore, the prior art needs to be improved. Summary of the invention

[0014] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a design method, device and medium for an electronically guided rubber-wheeled vehicle steering system. The design method solves the various shortcomings of the prior art mentioned above by constructing an objective function.

[0015] In order to solve the above technical problems, the present invention adopts the following technical solutions: According to one aspect of the present invention, a design method for an electronically guided rubber-wheeled vehicle steering system is provided, comprising: constructing a steering trapezoid with a length of a hypotenuse K and the length of the short side of the turning trapezoid L The objective function is the independent variable E( L , K ) ; Based on the objective function E( L , K ) Get the length of the hypotenuse of the turning trapezoid K and the length of the short side of the turning trapezoid L The optimal value of ( L , K ) , and according to the optimal value ( L , K ) The steering system of an electronically guided rubber-tyred vehicle is designed to improve the Ackerman correction rate of the steering system of an electronically guided rubber-tyred vehicle.

[0016] In one embodiment of the present invention, based on the objective function E( L , K ) Get the length of the hypotenuse of the turning trapezoid K and the short side length of the turned trapezoidL The optimal value of ( L , K ) The steps include: According to the objective function E( L , K ) Calculated ( L , K ) - E Data matrix; in accordance with ( L , K ) - E Data Matrix Plot ( L , K ) - E Surface plot; in accordance with ( L , K ) - E Surface plot to get the objective function E( L , K ) The minimum value of E( L , K ) The minimum value of the short side length of the turning trapezoid L and the length of the hypotenuse of the turning trapezoid K As the optimal value ( L , K ) .

[0017] In one embodiment of the present invention, according to the objective function E( L , K ) Calculated ( L , K ) - E The steps of data matrix include: according to the objective function E( L , K ) And calculated by three-dimensional matrix storage ( L , K ) - E Data matrix.

[0018] In one embodiment of the present invention, according to ( L , K ) - E The surface plot obtains the objective function E( L ,K ) The step of minimizing the value of the objective function also includes: using the extreme value method to E( L , K ) The minimum value is verified.

[0019] In one embodiment of the present invention, the objective function E( L , K ) include:

[0020] in,

[0021]

[0022]

[0023] in, L 0 is the vehicle wheelbase, M is the length of the long side of the turning trapezoid, i i is the inner wheel angle, i o2 It is the outer turning angle of the wheel based on the steering trapezoidal principle.

[0024] In one embodiment of the present invention, the outer turning angle of the wheel of the steering trapezoidal principle i o2 The first formula is used to obtain:

[0025]

[0026]

[0027]

[0028]

[0029] In one embodiment of the present invention, the method further comprises: based on the optimal value ( L , K ) And use the first formula to get the outer turning angle of the wheel based on the steering trapezoid principle i o2 Value i o3 , and i o3 Substituting into the second formula, we can get the Ackerman correction rate R A, the second formula includes: R A =( i o3 - i i ) / ( i o1 - i i ) in, i o1 It is the outer wheel turning angle according to Ackermann principle.

[0030] In one embodiment of the present invention, the Ackermann principle wheel outer angle i o1 According to the third formula, the third formula includes:

[0031] On the other hand, the present invention also provides a design device for an electronically guided rubber-wheeled vehicle steering system, comprising a memory, a processor, and program instructions stored in the memory for execution by the processor, wherein the processor executes the program instructions to implement any step of the above method.

[0032] On the other hand, the present invention further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the method described in any of the previous embodiments are performed.

[0033] By adopting the above technical solution, the present invention has the following advantages compared with the prior art: 1. By constructing the objective function E( L , K ) , the problem of no standard basis was solved, and the optimal steering system parameters were found by finding the minimum value of the function.

[0034] 2. By specifying the value range and step size of the short side length L of the turning trapezoid and the hypotenuse length K of the turning trapezoid, more optimization calculation comparison results are added, and the possibility of missing a better parameter value is avoided.

[0035] 3. Significantly improved the Ackerman correction rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A flow chart showing a design method of an electronically guided rubber-tyred vehicle steering system provided by the present invention; Figure 2 A comparison diagram of the Ackerman principle characteristic curve and the steering trapezoidal principle curve for different K values ​​provided by the present invention is shown; Figure 3 A comparison diagram of the Ackerman principle characteristic curve and the steering trapezoidal principle curve for different K values ​​provided by the present invention is shown; Figure 4 The surface diagram of the objective function E(L, K) provided by the present invention is shown; Figure 5 The Ackerman correction rate curve provided by the present invention is shown. DETAILED DESCRIPTION

[0037] It should be understood that the embodiments of the present invention shown in the exemplary embodiments are only illustrative. Although only a few embodiments are described in detail in the present invention, it is easy for those skilled in the art to appreciate that multiple modifications are feasible without actually departing from the teaching of the subject matter of the present invention. Accordingly, all such modifications should be included within the scope of the present invention. Without departing from the gist of the present invention, other replacements, modifications, changes and deletions may be made to the design, operating conditions and parameters of the following exemplary embodiments.

[0038] like Figure 1 As shown, the present invention provides a design method for an electronically guided rubber-wheeled vehicle steering system, comprising: constructing a steering trapezoid with a length of a hypotenuse K and the length of the short side of the turning trapezoid L The objective function is the independent variable E( L , K ) ; Based on the objective function E( L , K ) Get the length of the hypotenuse of the turning trapezoid K and the length of the short side of the turning trapezoid L The optimal value of ( L , K ) , and according to the optimal value ( L , K ) The steering system of an electronically guided rubber-tyred vehicle is designed to improve the Ackerman correction rate of the steering system of an electronically guided rubber-tyred vehicle.

[0039] The above technical solution of the invention constructs the objective function E( L , K ) , solved the problem of no standard basis, and found the optimal steering system parameters by finding the minimum value of the function; by stipulating the value range and step size of the short side length L of the steering trapezoid and the hypotenuse length K of the steering trapezoid, more optimization calculation comparison results were added, and the possibility of missing better parameter values ​​was avoided; and the Ackerman correction rate was significantly improved.

[0040] In the above method, if Figure 2As shown, the optimal value is obtained ( L , K ) The steps include: S1. Based on the objective function E( L , K ) Calculated ( L , K ) - E Data matrix; S2. Basis ( L , K ) - E Data Matrix Plot ( L , K ) - E Surface plot; S3. Basis ( L , K ) - E Surface plot to get the objective function E( L , K ) The minimum value of E( L , K ) The minimum value of the short side length of the turning trapezoid L and the length of the hypotenuse of the turning trapezoid K As the optimal value ( L , K ) .

[0041] In the above method, S1 includes: according to the objective function E( L , K ) And calculated by three-dimensional matrix storage ( L , K ) - E Data matrix.

[0042] In the above method, S3 also includes: using the extreme value method to calculate the objective function E( L , K ) The minimum value is verified.

[0043] In the above method, the objective function E( L , K ) include:

[0044] in,

[0045]

[0046]

[0047] in, L 0 is the vehicle wheelbase, M is the length of the long side of the turning trapezoid, i i is the inner wheel angle, i o2 It is the outer turning angle of the wheel based on the steering trapezoidal principle.

[0048] In the above method, the outer turning angle of the wheel of the steering trapezoidal principle i o2 The first formula is used to obtain:

[0049]

[0050]

[0051]

[0052]

[0053] In the above method, based on the optimal value ( L , K ) And use the first formula to get the outer turning angle of the wheel based on the steering trapezoid principle i o2 Value i o3 , and i o3 Substituting into the second formula, we can get the Ackerman correction rate R A , the second formula includes: R A =( i o3 - i i ) / ( i o1 - i i ) in, i o1 It is the outside turning angle of the wheel according to the Ackermann principle.

[0054] In the above method, the Ackerman principle wheel outer angle i o1 According to the third formula, the third formula includes:

[0055] On the other hand, the present invention also provides a design device for an electronically guided rubber-wheeled vehicle steering system, comprising a computer device, the computing device utilizing the content of any one of the above methods to obtain an optimal value. ( L , K ) , in order to improve the Ackerman correction rate of the steering system of the electronically guided rubber-wheeled vehicle.

[0056] In the above-mentioned design apparatus, the computer device includes a memory, a processor, and program instructions stored in the memory and executable by the processor, wherein the processor executes the program instructions to implement the steps of any one of the above-mentioned methods.

[0057] On the other hand, the present invention further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the method described in any of the previous embodiments are performed.

[0058] The following describes in detail how the present technical solution improves the Ackerman correction rate through specific embodiments.

[0059] (1) Select the steering system calculation parameters: minimum curve radius R 0 is 15m, vehicle wheelbase L 0 is 7m, the length of the long side of the turning trapezoid M 1554mm, the length of the inclined side of the turning trapezoid K Range 250-380mm, step length 5mm, short side length of turning trapezoid L Range 1303-1413mm, step length 5mm, wheel inner corner i i The range is -20-20° with a step size of 0.2°.

[0060] (2) According to the Ackermann principle, the outer wheel angle of the Ackermann principle is calculated according to formula 1. i 01 : Formula 1 is:

[0061] Calculated i o1 The range is -23.667—17.287°.

[0062] (3) According to the steering trapezoid principle, the outer steering angle of the steering trapezoid principle wheel is calculated according to Formula 2, Formula 3, Formula 4, Formula 5 and Formula 6. i o2 : Formula 2:

[0063] Formula 3:

[0064] Formula 4:

[0065] Formula 5:

[0066] Formula 6:

[0067] Calculated i o2 The range is -22.750—17.877°.

[0068] (4) The Ackerman principle characteristic curve is obtained according to the Ackerman principle curve equation, and the steering trapezoid principle curve is obtained according to the steering trapezoid principle curve equation. K Modify it to a fixed value, calculate the coordinates of each point on the Ackerman principle characteristic curve and the steering trapezoidal principle curve according to the formula equation group 1 and equation group 2, and draw a comparison chart, see the attached Figure 2 , Attachment Figure 3 .when K Value or L When the value changes, the difference between the Ackerman principle characteristic curve and the steering trapezoidal principle curve can be clearly found. The smaller the objective function value, the closer the steering trapezoidal principle characteristic curve is to the Ackerman principle characteristic curve.

[0069] Equation 1:

[0070] Equation 2:

[0071] (5) Objective function constructed based on equations 1 and 2 E( L , K ) , calculate different K Value and L The objective function value when the value is (L,K) The value of corresponds to the value of an objective function E. The present invention uses a three-dimensional matrix to store the calculated (L,K)-E relationship data, and obtain the data matrix. Draw according to the calculation results (L,K) -E surface plot, extract part of the data matrix as independent variable through matrix operation (L,K) , the dependent variable is the corresponding E value, see Appendix Figure 4 .

[0072] Objective Function E( L , K ) for:

[0073] in: y γ0 ( i i ) is the ordinate of the steering characteristic curve of the Ackerman principle, y γ ( L , K , i i ) is the ordinate of the steering characteristic curve of the steering trapezoidal principle.

[0074] The smaller the objective function value is, the closer the steering characteristic curve obtained by the steering trapezoidal principle is to the steering trapezoidal curve obtained by the Ackerman principle.

[0075] (6) Search on the drawn surface to find the minimum E value and its corresponding (L,K) The value is calculated and verified using the extreme value function. The results are the same. (L,K) The values ​​are both (1373,265).

[0076] (7) According to the optimization (L,K) = (1373,265) and other calculated parameters in (1), calculate the Ackerman correction rate: Draw the Ackerman correction rate curve according to the calculation results, see the attached Figure 5 . Use the length of the hypotenuse of the turning trapezoid corresponding to the minimum value of the objective function K and the length of the short side of the turning trapezoid L , calculate the Ackerman correction rate and draw a curve to find the minimum value of the Ackerman correction rate curve. After optimization, the Ackerman correction rate reaches 92.6%, which is a significant improvement compared to about 80%.

[0077] Compared with the prior art, the design method of this application constructs an objective function for steering characteristic curve comparison. E(L,K), the problem of no standard basis was solved, and the optimal steering system parameters were found by finding the minimum value of the function; by stipulating the value range and step size of the short side length L of the steering trapezoid and the hypotenuse length K of the steering trapezoid, more optimization calculation comparison results were added, and the possibility of missing better parameter values ​​was avoided; at the same time, the Ackerman correction rate was significantly improved.

[0078] Finally, it should be noted that a person skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods.

[0079] Furthermore, it should be appreciated that the computer-readable storage medium (eg, memory) herein may be either volatile memory or nonvolatile memory, or may include both volatile memory and nonvolatile memory.

[0080] It will also be appreciated by those skilled in the art that various exemplary logic blocks, modules, circuits and algorithm steps described in conjunction with the disclosure herein can be implemented as electronic hardware, computer software or a combination of the two. In order to clearly illustrate this interchangeability of hardware and software, a general description has been given to the functions of various schematic components, blocks, modules, circuits and steps. Whether this function is implemented as software or hardware depends on specific applications and the design constraints imposed on the entire system. Those skilled in the art can implement the function in various ways for each specific application, but this implementation decision should not be interpreted as causing a departure from the disclosed scope of the embodiments of the present invention.

[0081] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope disclosed in the embodiments of the present invention as defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0082] It should be understood that, as used herein, the singular forms "a", "an" are intended to include the plural forms as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations including one or more of the associated listed items.

[0083] The serial numbers of the embodiments disclosed in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0084] A person skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware or by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk or an optical disk, etc.

[0085] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the above embodiments of the present invention, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A design method for an electronically guided rubber-wheeled vehicle steering system, characterized in that: include: Constructed to turn the length of the hypotenuse of the trapezoid K and the length of the short side of the turning trapezoid L The objective function is the independent variable E( L , K ) ; Based on the objective function E( L , K ) Get the length of the hypotenuse of the turning trapezoid K and the short side length of the turned trapezoid L The optimal value of ( L , K ) , and according to the optimal value ( L , K ) The electronically guided rubber-wheeled vehicle steering system is designed to improve the Ackerman correction rate of the electronically guided rubber-wheeled vehicle steering system.

2. The design method of the electronically guided rubber-tyred vehicle steering system according to claim 1 is characterized in that: Based on the objective function E( L , K ) Get the length of the hypotenuse of the turning trapezoid K and the short side length of the turned trapezoid L The optimal value of ( L , K ) The steps include: According to the objective function E( L , K ) Calculated ( L , K ) - E Data matrix; According to the ( L , K ) - E Data Matrix Plot ( L , K ) - E Surface plot; According to the ( L , K ) - E The surface plot obtains the objective function E( L , K ) The minimum value of E( L , K ) The minimum value corresponds to the short side length of the turned trapezoid L and the length of the hypotenuse of the turning trapezoid K As the optimal value ( L , K ) .

3. The design method of the electronically guided rubber-tyred vehicle steering system according to claim 2 is characterized in that: According to the objective function E( L , K ) Calculated ( L , K ) - E The steps of the data matrix include: According to the objective function E( L , K ) And the calculation is obtained by storing the three-dimensional matrix ( L , K ) - E Data matrix.

4. The design method of the electronically guided rubber-tyred vehicle steering system according to claim 2 is characterized in that: According to the ( L , K ) - E The surface plot obtains the objective function E( L , K ) The minimum step also includes: The objective function is analyzed by using the extreme value method. E( L , K ) The minimum value is verified.

5. The design method of the electronically guided rubber-tyred vehicle steering system according to claim 2 is characterized in that: The objective function E( L , K ) include: in, in, L 0 is the vehicle wheelbase, M is the length of the long side of the turning trapezoid, θ i is the inner wheel angle, θ o2 It is the outer turning angle of the wheel based on the steering trapezoidal principle.

6. The design method of the electronically guided rubber-tyred vehicle steering system according to claim 5 is characterized in that: The outer wheel angle of the steering trapezoidal principle θ o2 Obtained using a first formula, the first formula comprising:

7. The design method of the electronically guided rubber-tyred vehicle steering system according to claim 6 is characterized in that: The method also includes: Based on the optimal value ( L , K ) And use the first formula to obtain the outer turning angle of the wheel of the steering trapezoid principle θ o2 Value θ o3 , and θ o3 Substituting into the second formula, we can get the Ackerman correction rate R A , the second formula includes: R A =（ θ o3 - θ i ） / ( θ o1 - θ i ) in, θ o1 It is the outer wheel turning angle according to Ackermann principle.

8. The design method of the electronically guided rubber-tyred vehicle steering system according to claim 7 is characterized in that: Ackermann Principle Wheel Outside Angle θ o1 Obtained according to the third formula, the third formula includes:

9. A design device for an electronically guided rubber-wheeled vehicle steering system, characterized in that: The method comprises a memory, a processor and program instructions stored in the memory and executable by the processor, wherein the processor executes the program instructions to implement the steps of the method according to any one of claims 1 to 8.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are performed.

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