Transverse control multi-control-algorithm switching method and system for motor sweeper

Abstract

The invention provides a transverse control multi-control-algorithm switching method and system for a motor sweeper. Relates to the technical field of vehicle transverse control. The method comprises the following steps: acquiring a current sweeper speed, and comparing the current sweeper speed with a set first vehicle speed threshold and a set second vehicle speed threshold; if the current speed of the sweeper is larger than or equal to the first speed threshold value, the sweeper is in a high-speed state, and a pure tracking control algorithm is selected to calculate the front wheel turning angle of the sweeper in the high-speed state to conduct transverse control over the sweeper; if the current speed of the sweeper is smaller than or equal to the second speed threshold value, the sweeper is in a low-speed state, and in the low-speed state, the PID control algorithm is selected to calculate the front wheel turning angle of the sweeper to conduct transverse control over the sweeper; if the current speed of the sweeper is larger than the second speed threshold value and smaller than the first speed threshold value, the weighting result of the pure tracking control algorithm and the PID control algorithm is selected as the final vehicle front wheel turning angle to conduct transverse control over the sweeper, and therefore the stability of the sweeper in the running process is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lateral control of a sweeper, and in particular to a method and system for switching multiple control algorithms for lateral control of a sweeper. Background Art

[0002] When designing the control strategy of an autonomous driving sweeper, a single control algorithm is usually selected or the pure tracking function of the sweeper is realized. The front wheel turning angle information and vehicle speed information of the sweeper are calculated by inputting the positioning information, reference trajectory information, and reference speed information into the control module. The control algorithm selected for lateral control in the control module usually uses a PID control algorithm or a pure tracking control algorithm. This control algorithm performs well in a low-speed straight-line driving state, but as the vehicle speed increases, the control effect of lateral control using the classic PID control algorithm gradually deteriorates, because the steady-state error of the PID control algorithm increases with the increase in speed, which may cause the lateral control of the vehicle to become unstable, and in severe cases, may cause the vehicle to suddenly yaw or even roll; in the pure tracking control algorithm, the vehicle speed that determines the front wheel turning angle of the vehicle is in the denominator. The smaller the speed, the larger the fraction. Based on the fractional inverse trigonometric function, the larger the front wheel turning angle of the vehicle is. Therefore, in the low-speed range, the vehicle stability is poor when the initial front wheel turning angle is large. Summary of the invention

[0003] In order to solve the above technical problem or at least partially solve the above technical problem, the present invention provides a method and system for switching multiple control algorithms for lateral control of a sweeper.

[0004] In a first aspect, the present invention provides a method for switching multiple control algorithms for lateral control of a sweeper, comprising:

[0005] Obtain the current speed of the sweeper, and compare the current speed of the sweeper with a set first speed threshold and a second speed threshold;

[0006] If the current speed of the sweeper is greater than or equal to the first speed threshold, the sweeper is in a high-speed state. In the high-speed state, a pure tracking control algorithm is used to calculate the front wheel turning angle of the vehicle to perform lateral control of the sweeper;

[0007] If the current speed of the sweeper is less than or equal to the second speed threshold, the sweeper is in a low-speed state, and the PID control algorithm is used to calculate the front wheel angle of the vehicle to perform lateral control of the sweeper in the low-speed state;

[0008] If the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, the pure tracking control algorithm and the PID control algorithm are used to calculate the final vehicle front wheel angle to perform lateral control of the sweeper, so as to improve the stability of the sweeper during operation.

[0009] Furthermore, the process of using the pure tracking control algorithm to calculate the front wheel steering angle of the vehicle to perform lateral control of the sweeper includes:

[0010] Get the wheelbase of the road sweeper;

[0011] The vehicle position information of the sweeper is obtained through the positioning module of the sweeper;

[0012] Outputting reference trajectory information through the trajectory planning module, and automatically selecting a preview point on the reference trajectory according to the vehicle speed;

[0013] Based on the preview point position and vehicle posture information, the angle between the center of the rear axle of the sweeper and the line connecting the preview point and the vehicle body and the shortest preview distance are obtained;

[0014] The vehicle front wheel turning angle calculated by the pure tracking control algorithm is as follows:

[0015]

[0016] Among them, δ pp is the front wheel turning angle of the vehicle calculated by the pure tracking control algorithm, L is the wheelbase of the sweeper; α is the angle between the center of the rear axle of the sweeper and the line connecting the preview point and the vehicle body; k is the speed coefficient; v is the current speed of the sweeper; l0 is the shortest preview distance;

[0017] The vehicle front wheel steering angle calculated by the pure tracking control algorithm is output to the vehicle chassis for execution, thereby achieving lateral control of the vehicle.

[0018] Furthermore, the process of using the PID control algorithm to calculate the front wheel steering angle of the vehicle to perform lateral control of the vehicle includes:

[0019] The vehicle position information of the sweeper is obtained through the positioning module of the sweeper;

[0020] Outputting reference trajectory information through the trajectory planning module, automatically selecting a preview point on the reference trajectory according to the vehicle speed, and obtaining the coordinates of the preview point and the current position of the vehicle;

[0021] Calculate the lateral error between the vehicle and the preview point based on the preview point and the vehicle's current posture information;

[0022] The lateral error e lat The input is given to the PID control algorithm to calculate the front wheel steering angle of the vehicle. The calculation formula is:

[0023]

[0024] Among them, δ pid is the front wheel steering angle of the vehicle calculated by the PID control algorithm, k p is the proportional coefficient of the PID control algorithm; ki is the integral coefficient of the PID control algorithm; k d is the differential coefficient of the PID control algorithm; e lat (k) is the lateral error at time k; e lat (k-1) is the lateral error at time k-1; e lat (m) is the lateral error at time m.

[0025] Furthermore, the calculation formula of the lateral error is:

[0026] dx=x pre -x cur

[0027] dy=y pre -y cur ,

[0028]

[0029] θ e =θ-θ cur ,

[0030]

[0031] e lat = l d sinθ e ,

[0032] Among them, x pre is the horizontal coordinate of the preview point; pre is the vertical coordinate of the preview point; cur is the horizontal coordinate of the vehicle's current position; cur is the ordinate of the vehicle's current position; dx is the difference between the preview point and the vehicle's current position; dy is the difference between the preview point and the vehicle's current position; θ is the angle between the vehicle's current position and the preview point; θ cur is the heading angle of the vehicle’s current position; θ e is the difference between the angle between the current position of the vehicle and the line connecting the preview point and the heading angle of the current position of the vehicle; l d is the straight-line distance between the vehicle's current position and the preview point; e lat is the lateral error.

[0033] Furthermore, the process of selecting the weighted results of the pure tracking control algorithm and the PID control algorithm for lateral control of the sweeper includes:

[0034] When the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, the front wheel turning angle of the vehicle is calculated by the pure tracking control algorithm and the PID control algorithm at the same time;

[0035] The weights of the pure tracking control algorithm and the PID control algorithm for calculating the front wheel steering angle of the vehicle are obtained based on the current speed of the sweeper; the calculation formula of the front wheel steering angle of the vehicle calculated by the pure tracking control algorithm and the PID control algorithm is:

[0036] δ=w1δ pid +w2δ pp ,vth2 <v<vth1;

[0037] Among them, w1 is the weight of the vehicle front wheel steering angle calculated by the PID control algorithm; w2 is the weight of the vehicle front wheel steering angle calculated by the pure tracking control algorithm; δ is the final calculated vehicle front wheel steering angle;

[0038] The final vehicle front wheel steering angle is output to the vehicle chassis for execution.

[0039] Furthermore, the calculation formula of the weight w1 of the vehicle's front wheel steering angle calculated by the PID control algorithm is: w1=k1(th1-v), where k1 is a constant coefficient; the calculation formula of the weight w2 of the vehicle's front wheel steering angle calculated by the pure tracking control algorithm is: w2=k2(v-th2), where k2 is a constant coefficient.

[0040] Furthermore, regardless of the speed of the sweeper, the front wheel angle of the vehicle is calculated by the pure tracking control algorithm and the PID control algorithm at the same time;

[0041] The global weight of the vehicle front wheel turning angle obtained by the pure tracking control algorithm and the PID control algorithm is obtained according to the speed of the sweeper;

[0042] Among them, the global weight w1 of the vehicle front wheel angle calculated by the PID control algorithm is g The calculation formula is:

[0043]

[0044] In the formula, k1 is a constant coefficient;

[0045] The global weight w2 of the vehicle front wheel steering angle calculated by the pure tracking control algorithm g The calculation formula is:

[0046]

[0047] In the formula, k2 is a constant coefficient;

[0048] At any vehicle speed, the calculation formula for the vehicle front wheel angle calculated by the pure tracking control algorithm and the PID control algorithm is:

[0049]

[0050] The final vehicle front wheel steering angle is output to the vehicle chassis for execution.

[0051] In a second aspect, the present invention provides a lateral control multi-control algorithm switching system for a sweeper, comprising:

[0052] A lateral control module formed by a PID control algorithm unit, a pure tracking control algorithm unit and a multi-control algorithm switching unit, and a chassis execution module connected to the lateral control module;

[0053] Wherein, the PID control algorithm unit calculates the front wheel steering angle of the vehicle based on the PID control algorithm;

[0054] The pure tracking control algorithm unit calculates the front wheel steering angle of the vehicle based on the pure tracking control algorithm;

[0055] The multi-control algorithm switching unit obtains the current speed of the sweeper, and compares the current speed of the sweeper with the set first speed threshold and the second speed threshold; if the current speed of the sweeper is greater than or equal to the first speed threshold, the pure tracking control algorithm is used to calculate the front wheel steering angle of the vehicle to perform lateral control of the sweeper; if the current speed of the sweeper is less than or equal to the second speed threshold, the PID control algorithm is used to calculate the front wheel steering angle of the vehicle to perform lateral control of the sweeper; if the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, the pure tracking control algorithm and the PID control algorithm are used to calculate the final front wheel steering angle of the vehicle to perform lateral control of the sweeper;

[0056] The chassis execution module executes the vehicle front wheel steering angle output by the lateral control module.

[0057] Furthermore, the lateral control module is connected to the positioning module, the speed detection module, the trajectory planning module and the chassis execution module, the positioning module provides the vehicle posture information required to implement the multi-control algorithm switching method for the lateral control of the sweeper, the trajectory planning module provides the reference trajectory information required to implement the multi-control algorithm switching method for the lateral control of the sweeper, and the speed detection module provides the current sweeper speed required to implement the multi-control algorithm switching method for the lateral control of the sweeper.

[0058] In the third aspect, the present invention provides a device for switching multiple control algorithms for the lateral control of a sweeper, comprising: at least one processing unit, which connects the processing unit and the storage unit through a bus unit. The storage unit is a computer-readable storage medium that can be used to store software programs, computer executable programs and modules. The processing unit implements the method for switching multiple control algorithms for the lateral control of the sweeper by running the software programs, computer executable programs and modules stored in the storage unit.

[0059] The above technical solution provided by the embodiment of the present invention has the following advantages compared with the prior art:

[0060] The present application obtains the current speed of the sweeper, and compares the current speed of the sweeper with the set first speed threshold and second speed threshold; if the current speed of the sweeper is greater than or equal to the first speed threshold, the sweeper is in a high-speed state, and a pure tracking control algorithm is used to calculate the front wheel turning angle of the vehicle to perform lateral control of the sweeper in the high-speed state; if the current speed of the sweeper is less than or equal to the second speed threshold, the sweeper is in a low-speed state, and a PID control algorithm is used to calculate the front wheel turning angle of the vehicle to perform lateral control of the sweeper in the low-speed state; if the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, a weighted result of a pure tracking control algorithm and a PID control algorithm is used as the final front wheel turning angle of the vehicle to perform lateral control of the sweeper, thereby improving the stability of the sweeper during operation. The present application combines the advantages of the PID control algorithm and the pure tracking control algorithm in different speed ranges, effectively avoiding the sudden yaw caused by error diffusion of the PID control algorithm in the high-speed state range, and effectively avoiding the problem of large front wheel turning angle of the vehicle in the low-speed state range of the pure tracking control algorithm. The present application uses the PID control algorithm and the pure tracking control algorithm to calculate the weighted result of the front wheel turning angle of the vehicle between the high-speed state and the low-speed state, further increasing the smoothness of the transition process. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0062] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0063] Figure 1 A flow chart of a method for switching multiple control algorithms for lateral control of a road sweeper provided by an embodiment of the present invention;

[0064] Figure 2 A flow chart of a pure tracking control algorithm provided in an embodiment of the present invention for calculating the front wheel steering angle of a vehicle to perform lateral control of a sweeper;

[0065] Figure 3 A flow chart of a PID control algorithm provided in an embodiment of the present invention for calculating the front wheel steering angle of a vehicle to perform lateral control of the vehicle;

[0066] Figure 4 A flowchart of combining a pure tracking control algorithm and a PID control algorithm to calculate the front wheel angle of a vehicle to perform lateral control of a sweeper provided in an embodiment of the present invention;

[0067] Figure 5 A flowchart of calculating the final vehicle front wheel steering angle based on the global weight of the vehicle front wheel steering angle to perform lateral control provided by an embodiment of the present invention;

[0068] Figure 6 A schematic diagram of a multi-control algorithm switching system for lateral control of a road sweeper provided by an embodiment of the present invention;

[0069] Figure 7 A schematic diagram of a multi-control algorithm switching device for lateral control of a sweeper provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0070] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0072] Example 1

[0073] like Figure 1 As shown, the technology of the present invention realizes a method for switching multiple control algorithms for lateral control of a sweeper, and the present invention includes the following steps:

[0074] The current speed v of the sweeper is obtained, and the current speed v of the sweeper is compared with the set first speed threshold vth1 and second speed threshold vth2.

[0075] Case 1: If the current speed v of the sweeper is greater than or equal to the first speed threshold vth1, the sweeper is in a high-speed state. In this state, a pure tracking control algorithm is used to perform lateral control of the sweeper.

[0076] The vehicle front wheel steering angle calculated by the pure tracking control algorithm is output to the vehicle chassis for execution, thereby achieving lateral control of the vehicle.

[0077] Case 2: If the current speed of the sweeper is less than or equal to the second speed threshold, the sweeper is in a low-speed state. In the low-speed state, the PID control algorithm is used to perform lateral control of the sweeper.

[0078] Case 3: If the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, the weighted result of the pure tracking control algorithm and the PID control algorithm is selected as the final calculated vehicle front wheel angle to perform lateral control of the sweeper, so as to improve the stability of the sweeper during operation.

[0079] In one embodiment:

[0080] When the current speed v of the sweeper is greater than or equal to the first speed threshold vth1, only the pure tracking control algorithm is executed to calculate the front wheel steering angle of the vehicle to perform lateral control of the sweeper, such as Figure 2 As shown, the process includes:

[0081] Get the wheelbase of the road sweeper;

[0082] The vehicle position information of the sweeper is obtained through the positioning module of the sweeper;

[0083] Outputting reference trajectory information through a trajectory planning module, and selecting a preview point on the reference trajectory according to the vehicle speed;

[0084] Based on the preview point position and vehicle posture information, the angle between the center of the rear axle of the sweeper and the line connecting the preview point and the vehicle body and the shortest preview distance are obtained;

[0085] The vehicle front wheel turning angle calculated by the pure tracking control algorithm is as follows:

[0086]

[0087] Among them, δ pp is the front wheel turning angle of the vehicle calculated by the pure tracking control algorithm, L is the wheelbase of the sweeper; α is the angle between the center of the rear axle of the sweeper and the line connecting the preview point and the vehicle body; k is the speed coefficient; v is the vehicle speed; l0 is the shortest preview distance.

[0088] When the current speed of the sweeper is less than or equal to the second speed threshold, only the PID control algorithm is executed to calculate the front wheel steering angle of the vehicle to perform lateral control of the vehicle, such as Figure 3 As shown, the process includes:

[0089] The vehicle position information of the sweeper is obtained through the positioning module of the sweeper;

[0090] Outputting reference trajectory information through the trajectory planning module, automatically selecting a preview point on the reference trajectory according to the vehicle speed, and obtaining the coordinates of the preview point and the current position of the vehicle;

[0091] The lateral error between the two points is calculated based on the preview point and the vehicle's current posture information; the lateral error calculation formula is:

[0092] dx=x pre -x cur

[0093] dy=y pre -y cur ,

[0094]

[0095] θ e =θ-θ cur ,

[0096]

[0097] e lat = l d sinθ e ,

[0098] Among them, x pre is the horizontal coordinate of the preview point; pre is the vertical coordinate of the preview point; cur is the horizontal coordinate of the vehicle's current position; cur is the ordinate of the vehicle's current position; dx is the difference between the preview point and the vehicle's current position; dy is the difference between the preview point and the vehicle's current position; θ is the angle between the vehicle's current position and the preview point; θ cur is the heading angle of the vehicle’s current position; θ e is the difference between the angle between the current position of the vehicle and the line connecting the preview point and the heading angle of the current position of the vehicle; l d is the straight-line distance between the vehicle's current position and the preview point; e lat is the lateral error.

[0099] The lateral error e lat The input is given to the PID control algorithm to calculate the front wheel steering angle of the vehicle. The calculation formula is:

[0100]

[0101] Among them, δ pid is the front wheel steering angle of the vehicle calculated by the PID control algorithm, k p is the proportional coefficient of the PID control algorithm; k i is the integral coefficient of the PID control algorithm; k d is the differential coefficient of the PID control algorithm; e lat (k) is the lateral error at time k; e lat (k-1) is the lateral error at time k-1; e lat(m) is the lateral error at time m.

[0102] The vehicle front wheel steering angle calculated by the PID control algorithm is output to the vehicle chassis for execution to achieve lateral control of the vehicle.

[0103] When the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, the front wheel steering angle of the vehicle is calculated by combining the pure tracking control algorithm and the PID control algorithm to perform lateral control of the sweeper, such as Figure 4 As shown, the process includes:

[0104] When the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, the front wheel turning angle of the vehicle is calculated by the pure tracking control algorithm and the PID control algorithm at the same time;

[0105] The weight of the vehicle front wheel steering angle is calculated by the pure tracking control algorithm and the PID control algorithm based on the current vehicle speed of the sweeper; in the specific implementation process, the calculation formula of the weight w1 of the vehicle front wheel steering angle calculated by the PID control algorithm is: w1=k1(th1-v), where k1 is a constant coefficient; the calculation formula of the weight w2 of the vehicle front wheel steering angle calculated by the pure tracking control algorithm is: w2=k2(v-th2), where k2 is a constant coefficient;

[0106] The calculation formula of the vehicle front wheel angle calculated by the pure tracking control algorithm and the PID control algorithm is:

[0107] δ=w1δ pid +w2δ pp ,vth2 <v<vth1;

[0108] Among them, w1 is the weight of the vehicle's front wheel steering angle calculated by the PID control algorithm; w2 is the weight of the vehicle's front wheel steering angle calculated by the pure tracking control algorithm; δ is the final calculated vehicle front wheel steering angle.

[0109] The final front wheel steering angle of the vehicle is output to the vehicle chassis for execution. After the chassis executes the corresponding lateral control command, the driving stability of the vehicle can be effectively improved.

[0110] In another embodiment: Figure 5 As shown, the final vehicle front wheel steering angle is calculated based on the global weight of the vehicle front wheel steering angle to perform lateral control, including:

[0111] Regardless of the speed of the sweeper, the front wheel angle of the vehicle is calculated by the pure tracking control algorithm and the PID control algorithm at the same time;

[0112] The global weight of the vehicle front wheel turning angle obtained by the pure tracking control algorithm and the PID control algorithm is obtained according to the speed of the sweeper;

[0113] Among them, the global weight of the vehicle front wheel angle calculated by the PID control algorithm is The calculation formula is:

[0114]

[0115] In the formula, k1 is a constant coefficient;

[0116] The global weight of the vehicle's front wheel steering angle calculated by the pure tracking control algorithm The calculation formula is:

[0117]

[0118] In the formula, k2 is a constant coefficient;

[0119] At any vehicle speed, the calculation formula for the vehicle front wheel angle calculated by the pure tracking control algorithm and the PID control algorithm is:

[0120]

[0121] The obtained vehicle front wheel steering angle is output to the vehicle chassis for execution.

[0122] Example 2

[0123] See also Figure 6 As shown, an embodiment of the present invention provides a lateral control multi-control algorithm switching system for a sweeper, comprising:

[0124] A lateral control module formed by a PID control algorithm unit, a pure tracking control algorithm unit and a multi-control algorithm switching unit is connected to a chassis execution module, a positioning module, a speed detection module and a trajectory planning module of the lateral control module;

[0125] The positioning module provides the vehicle posture information required to implement the method for switching multiple control algorithms for lateral control of the sweeper, the trajectory planning module provides the reference trajectory information required to implement the method for switching multiple control algorithms for lateral control of the sweeper, and the speed detection module provides the current speed of the sweeper required to implement the method for switching multiple control algorithms for lateral control of the sweeper.

[0126] The PID control algorithm unit calculates the front wheel steering angle of the vehicle based on the PID control algorithm;

[0127] The pure tracking control algorithm unit calculates the front wheel steering angle of the vehicle based on the pure tracking control algorithm;

[0128] The multi-control algorithm switching unit obtains the current speed of the sweeper, and compares the current speed of the sweeper with the set first speed threshold and the second speed threshold; if the current speed of the sweeper is greater than or equal to the first speed threshold, the pure tracking control algorithm is used to calculate the front wheel steering angle of the vehicle to perform lateral control of the sweeper; if the current speed of the sweeper is less than or equal to the second speed threshold, the PID control algorithm is used to calculate the front wheel steering angle of the vehicle to perform lateral control of the sweeper; if the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, the pure tracking control algorithm and the PID control algorithm are used to calculate the final front wheel steering angle of the vehicle to perform lateral control of the sweeper;

[0129] The chassis execution module executes the vehicle front wheel steering angle output by the lateral control module.

[0130] Example 3

[0131] See also Figure 7 As shown, an embodiment of the present invention provides a device for switching multiple control algorithms for lateral control of a road sweeper, comprising: at least one processing unit, a processing unit, a storage unit, and the storage unit as a computer-readable storage medium, which can be used to store software programs, computer executable programs, and modules, such as the software programs, computer executable programs, and modules corresponding to a method for switching multiple control algorithms for lateral control of a road sweeper in an embodiment of the present invention. The processing unit implements the above-mentioned method for switching multiple control algorithms for lateral control of a road sweeper by running the software programs, computer executable programs, and modules stored in the storage unit, comprising:

[0132] Obtain the current speed of the sweeper, and compare the current speed of the sweeper with a set first speed threshold and a second speed threshold;

[0133] If the current speed of the sweeper is greater than or equal to the first speed threshold, the sweeper is in a high-speed state, and a pure tracking control algorithm is used to perform lateral control of the sweeper in the high-speed state;

[0134] If the current speed of the sweeper is less than or equal to the second speed threshold, the sweeper is in a low-speed state, and the PID control algorithm is used to perform lateral control of the sweeper in the low-speed state;

[0135] If the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, the weighted result of the pure tracking control algorithm and the PID control algorithm is used to perform lateral control of the sweeper to improve the stability of the sweeper during operation.

[0136] Of course, the computer program stored in the storage unit of the multi-control algorithm switching device for lateral control of a sweeper provided in an embodiment of the present invention is not limited to the operation of the method described above, but can also execute the related operations in the multi-control algorithm switching method for lateral control of a sweeper provided in any embodiment of the present invention.

[0137] Example 4

[0138] An embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program. When the computer program is executed, the method for switching multiple control algorithms for lateral control of a road sweeper is implemented, including:

[0139] Obtain the current speed of the sweeper, and compare the current speed of the sweeper with a set first speed threshold and a second speed threshold;

[0140] If the current speed of the sweeper is greater than the first speed threshold, the sweeper is in a high-speed state, and the pure tracking control algorithm is used to perform lateral control of the sweeper in the high-speed state;

[0141] If the current speed of the sweeper is less than the second speed threshold, the sweeper is in a low-speed state. In the low-speed state, the PID control algorithm is used to perform lateral control of the sweeper;

[0142] If the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, the weighted result of the pure tracking control algorithm and the PID control algorithm is used to perform lateral control of the sweeper to improve the stability of the sweeper during operation.

[0143] A computer-readable storage medium provided in an embodiment of the present invention stores a computer program which is not limited to the method operations described above, but can also execute related operations in a method for switching multiple control algorithms for lateral control of a road sweeper provided in any embodiment of the present invention.

[0144] In the embodiments provided by the present invention, it should be understood that the disclosed structures and methods can be implemented in other ways. For example, the structural embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, structures or units, which can be electrical, mechanical or other forms.

[0145] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0146] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0147] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for switching multiple control algorithms for lateral control of a road sweeper, characterized in that: include: Obtain the current speed of the sweeper, and compare the current speed of the sweeper with a set first speed threshold and a second speed threshold; If the current speed of the sweeper is greater than or equal to the first speed threshold, the sweeper is in a high-speed state. In the high-speed state, a pure tracking control algorithm is used to calculate the front wheel turning angle of the vehicle to perform lateral control of the sweeper. If the current speed of the sweeper is less than or equal to the second speed threshold, the sweeper is in a low-speed state, and the PID control algorithm is used to calculate the front wheel angle of the vehicle to perform lateral control of the sweeper in the low-speed state; If the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, the pure tracking control algorithm and PID control algorithm are used to calculate the front wheel angle of the vehicle to perform lateral control of the sweeper, so as to improve the stability of the sweeper during operation.

2. The method for switching multiple control algorithms for lateral control of a sweeper according to claim 1, characterized in that: The process of using the pure tracking control algorithm to calculate the front wheel angle of the vehicle to perform lateral control of the sweeper includes: Get the wheelbase of the road sweeper; The vehicle position information of the sweeper is obtained through the positioning module of the sweeper; Outputting reference trajectory information through the trajectory planning module, and automatically selecting a preview point on the reference trajectory according to the vehicle speed; Based on the preview point position and vehicle posture information, the angle between the center of the rear axle of the sweeper and the line connecting the preview point and the vehicle body and the shortest preview distance are obtained; The vehicle front wheel turning angle calculated by the pure tracking control algorithm is as follows: Among them, δ pp is the front wheel turning angle of the vehicle calculated by the pure tracking control algorithm, L is the wheelbase of the sweeper; α is the angle between the center of the rear axle of the sweeper and the line connecting the preview point and the vehicle body; k is the speed coefficient; v is the current speed of the sweeper; l0 is the shortest preview distance; The vehicle front wheel steering angle calculated by the pure tracking control algorithm is output to the vehicle chassis for execution, thereby achieving lateral control of the vehicle.

3. The method for switching multiple control algorithms for lateral control of a sweeper according to claim 1, characterized in that: The process of using the PID control algorithm to calculate the front wheel steering angle of the vehicle to perform lateral control of the vehicle includes: The vehicle position information of the sweeper is obtained through the positioning module of the sweeper; Outputting reference trajectory information through the trajectory planning module, automatically selecting a preview point on the reference trajectory according to the vehicle speed, and obtaining the coordinates of the preview point and the current position of the vehicle; Calculate the lateral error between the vehicle and the preview point based on the preview point and the vehicle's current posture information; The lateral error e lat The input is given to the PID control algorithm to calculate the front wheel steering angle of the vehicle. The calculation formula is: Among them, δ pid is the front wheel steering angle of the vehicle calculated by the PID control algorithm, k p is the proportional coefficient of the PID control algorithm; k i is the integral coefficient of the PID control algorithm; k d is the differential coefficient of the PID control algorithm; e lat (k) is the lateral error at time k; e lat (k-1) is the lateral error at time k-1; e lat (m) is the lateral error at time m.

4. The method for switching multiple control algorithms for lateral control of a sweeper according to claim 3 is characterized in that: The calculation formula of the lateral error is: dx=x pre -x cur dy=y pre -the cur , i e =θ-θ cur , And lat =l d sinθ e , Among them, x pre is the horizontal coordinate of the preview point; pre is the vertical coordinate of the preview point; cur is the horizontal coordinate of the vehicle's current position; cur is the ordinate of the vehicle's current position; dx is the difference between the preview point and the vehicle's current position; dy is the difference between the preview point and the vehicle's current position; θ is the angle between the vehicle's current position and the preview point; θ cur is the heading angle of the vehicle’s current position; θ e is the difference between the angle between the current position of the vehicle and the line connecting the preview point and the heading angle of the current position of the vehicle; l d is the straight-line distance between the vehicle's current position and the preview point; e lat is the lateral error.

5. The method for switching multiple control algorithms for lateral control of a sweeper according to claim 1, characterized in that: When the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, the process of using the pure tracking control algorithm and the PID control algorithm to calculate the final vehicle front wheel turning angle to perform lateral control of the sweeper includes: When the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, the front wheel turning angle of the vehicle is calculated by the pure tracking control algorithm and the PID control algorithm at the same time; The weights of the pure tracking control algorithm and the PID control algorithm for calculating the front wheel steering angle of the vehicle are obtained based on the current speed of the sweeper; the calculation formula of the front wheel steering angle of the vehicle calculated by the pure tracking control algorithm and the PID control algorithm is: δ=w1δ pid +w2d pp ,vth2 <v<vth1; Among them, w1 is the weight of the vehicle front wheel steering angle calculated by the PID control algorithm; w2 is the weight of the vehicle front wheel steering angle calculated by the pure tracking control algorithm; δ is the final calculated vehicle front wheel steering angle; The final vehicle front wheel steering angle is output to the vehicle chassis for execution.

6. The method for switching multiple control algorithms for lateral control of a sweeper according to claim 5, characterized in that: The calculation formula for the weight w1 of the vehicle's front wheel steering angle calculated by the PID control algorithm is: w1=k1(th1-v), where k1 is a constant coefficient; the calculation formula for the weight w2 of the vehicle's front wheel steering angle calculated by the pure tracking control algorithm is: w2=k2(v-th2), where k2 is a constant coefficient.

7. The method for switching multiple control algorithms for lateral control of a sweeper according to claim 1, characterized in that: Regardless of the speed of the sweeper, the front wheel angle of the vehicle is calculated by the pure tracking control algorithm and the PID control algorithm at the same time; The global weight of the vehicle front wheel turning angle obtained by the pure tracking control algorithm and the PID control algorithm is obtained according to the speed of the sweeper; Among them, the global weight of the vehicle front wheel angle calculated by the PID control algorithm is The calculation formula is: In the formula, k1 is a constant coefficient; The global weight of the vehicle's front wheel steering angle calculated by the pure tracking control algorithm The calculation formula is: In the formula, k2 is a constant coefficient; At any vehicle speed, the calculation formula for the vehicle front wheel angle calculated by the pure tracking control algorithm and the PID control algorithm is: The obtained vehicle front wheel steering angle is output to the vehicle chassis for execution.

8. A multi-control algorithm switching system for lateral control of a sweeper, characterized in that: include: A lateral control module formed by a PID control algorithm unit, a pure tracking control algorithm unit and a multi-control algorithm switching unit, and a chassis execution module connected to the lateral control module; Wherein, the PID control algorithm unit calculates the front wheel steering angle of the vehicle based on the PID control algorithm; The pure tracking control algorithm unit calculates the front wheel steering angle of the vehicle based on the pure tracking control algorithm; The multi-control algorithm switching unit obtains the current speed of the sweeper, and compares the current speed of the sweeper with the set first speed threshold and the second speed threshold; if the current speed of the sweeper is greater than or equal to the first speed threshold, the pure tracking control algorithm is used to calculate the front wheel steering angle of the vehicle to perform lateral control of the sweeper; if the current speed of the sweeper is less than or equal to the second speed threshold, the PID control algorithm is used to calculate the front wheel steering angle of the vehicle to perform lateral control of the sweeper; if the current speed of the sweeper is greater than the second speed threshold and less than the first speed threshold, the pure tracking control algorithm and the PID control algorithm are used to calculate the final front wheel steering angle of the vehicle to perform lateral control of the sweeper; The chassis execution module executes the vehicle front wheel steering angle output by the lateral control module.

9. The lateral control multi-control algorithm switching system for a sweeper according to claim 8, characterized in that: The lateral control module is connected to the positioning module, the speed detection module and the trajectory planning module. The positioning module provides the vehicle posture information required to implement the multi-control algorithm switching method for the lateral control of the sweeper. The trajectory planning module provides the reference trajectory information required to implement the multi-control algorithm switching method for the lateral control of the sweeper. The speed detection module provides the current speed of the sweeper required to implement the multi-control algorithm switching method for the lateral control of the sweeper.

10. A device for switching multiple control algorithms for lateral control of a road sweeper, characterized in that: include: At least one processing unit connects the processing unit and the storage unit through a bus unit. The storage unit is a computer-readable storage medium that can be used to store software programs, computer executable programs and modules. The processing unit runs the software programs, computer executable programs and modules stored in the storage unit, thereby implementing the method for switching multiple control algorithms for lateral control of a sweeper as described in any one of claims 1 to 7.

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