A longitudinal and lateral control method and system for intelligent horizontal transport vehicles in ports

Abstract

The present invention discloses a longitudinal and transverse control method and system for a port intelligent horizontal transport vehicle, comprising: establishing a transverse two-degree-of-freedom single-track dynamic model of the port intelligent horizontal transport vehicle by uniformly setting the system performance of the port intelligent horizontal transport vehicle; constructing a transverse and longitudinal control system of the port intelligent horizontal transport vehicle according to the actual operating conditions of the port intelligent horizontal transport vehicle; and designing a disturbance observer and a corresponding sliding mode controller in the transverse and longitudinal control system of the port intelligent horizontal transport vehicle based on the transverse and longitudinal control system of the port intelligent horizontal transport vehicle to realize hierarchical decoupling control of the vehicle. The present invention can significantly improve system robustness, driving safety, control accuracy and container transshipment efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of path tracking control for port intelligent horizontal transport vehicles, and in particular to a longitudinal and lateral control method and system for port intelligent horizontal transport vehicles. Background Art

[0002] In recent years, with the surge in maritime trade volume around the world, ports' requirements for container terminal cargo throughput capacity have also been rising year by year. As a horizontal transportation equipment with autonomous motion capabilities, port intelligent horizontal transport vehicles have become the most important transfer tool for automated container terminals. However, how to ensure the motion control accuracy and stability of port intelligent horizontal transport vehicles in strong interference environments such as high humidity, high salt fog, and multi-metal objects in the port, so as to achieve rapid adaptation with loading and unloading equipment, is a pain point that needs to be solved in this field. In response to this type of problem, a large number of scientific researchers have carried out exploratory research and accumulated some valuable results. At present, the existing solutions to this type of problem in the field of engineering applications are mainly interference suppression; interference suppression mainly relies on the robustness and adaptability of the control algorithm itself to passively resist the influence of interference. The mainstream algorithms include proportional-integral-differential control, sliding mode control, model predictive control, etc. The above passive anti-interference control method has certain limitations. Since the control quantity is generated after the interference, the control process has a certain lag compared to the interference, so it is easy to produce a large overshoot, and the control accuracy is difficult to guarantee in a complex environment.

[0003] Intelligent horizontal transport vehicles at ports are easily affected by multiple sources of interference during operation, such as ambient noise, communication delay, model parameter perturbation, electromagnetic signal disturbance, etc., which cause problems such as bumpy transportation process, large external impact on containers, and poor parking accuracy, hindering the further improvement of the operating efficiency of automated container terminals. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above existing problems, the present invention is proposed.

[0006] Therefore, the present invention provides a longitudinal and lateral control method and system for port intelligent horizontal transport vehicles to solve the problems of poor motion control accuracy and container transfer efficiency of port intelligent horizontal transport vehicles in existing complex operating environments.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] In a first aspect, the present invention provides a longitudinal and lateral control method for a port intelligent horizontal transport vehicle, comprising:

[0009] By uniformly setting the system performance of the port intelligent horizontal transport vehicle, a lateral two-degree-of-freedom single-track dynamic model of the port intelligent horizontal transport vehicle is established;

[0010] According to the actual operating conditions of the port intelligent horizontal transport vehicles, the horizontal and vertical control system of the port intelligent horizontal transport vehicles is constructed;

[0011] Based on the transverse and longitudinal control systems of the port intelligent horizontal transport vehicles, the disturbance observer and the corresponding sliding mode controller in the transverse and longitudinal control systems of the port intelligent horizontal transport vehicles are designed respectively to realize the hierarchical decoupling control of the vehicles.

[0012] As a preferred solution of the longitudinal and lateral control method of the port intelligent horizontal transportation vehicle of the present invention, the lateral two-degree-of-freedom single-track dynamic model of the port intelligent horizontal transportation vehicle is expressed as:

[0013]

[0014] in, represents the lateral velocity of the port intelligent horizontal transport vehicle in the world coordinate system, v x represents the longitudinal velocity of the port intelligent horizontal transport vehicle in the vehicle body coordinate system, v y represents the lateral speed of the port intelligent horizontal transport vehicle in the body coordinate system, It represents the actual heading angle of the port intelligent horizontal transport vehicle in the world coordinate system. represents the lateral acceleration of the port intelligent horizontal transport vehicle in the body coordinate system, m represents the total mass of the port intelligent horizontal transport vehicle, C cf With C cr Represent the cornering stiffness of the front and rear axle tires, s f represents the slip rate of the front axle tire, δ f and δ r They represent the front and rear wheel turning angles of the port intelligent horizontal transport vehicle, α f With α r They represent the side slip angles of the front and rear wheels of the port intelligent horizontal transport vehicle, represents the yaw angular velocity of the port intelligent horizontal transport vehicle, l f and l r They represent the distances from the front and rear axles to the center of mass of the port intelligent horizontal transport vehicle, I z represents the moment of inertia of the port intelligent horizontal transport vehicle around the z-axis, It represents the yaw angular acceleration of the port intelligent horizontal transport vehicle;

[0015] The lateral two-degree-of-freedom single-track dynamics model of the port intelligent horizontal transport vehicle is rewritten into the state equation form as follows:

[0016]

[0017] Among them, x represents the state quantity of the control system, represents the derivative of the control quantity in the time domain, A represents the state transfer matrix, B represents the input matrix, u represents the system control quantity, d represents the system interference term, y represents the system output, and C represents the output matrix.

[0018] As a preferred solution of the longitudinal and lateral control method of the port intelligent horizontal transport vehicle described in the present invention, wherein: according to the actual operating conditions of the port intelligent horizontal transport vehicle, a longitudinal and lateral control system of the port intelligent horizontal transport vehicle is constructed, wherein the main control parameters of the lateral control system of the port intelligent horizontal transport vehicle are:

[0019] Y2=YY ref

[0020]

[0021] Among them, Y e , Y and Y ref They represent the lateral deviation, actual lateral coordinate and reference lateral coordinate of the port intelligent horizontal transport vehicle in the world coordinate system respectively; similarly, and They respectively represent the heading angle deviation, actual heading angle and reference heading angle of the port intelligent horizontal transport vehicle in the world coordinate system.

[0022] As a preferred solution of the longitudinal and lateral control method of the port intelligent horizontal transport vehicle of the present invention, the disturbance observer for designing the lateral control system of the port intelligent horizontal transport vehicle is expressed as:

[0023]

[0024] in, is the estimated value of the disturbance d, ξ is the intermediate variable, and L represents the observer gain matrix;

[0025] The interference error is defined as:

[0026]

[0027] in, represents the interference error, is the differential of the interference error with respect to time. Similarly, and They represent the differentials of the estimated disturbance value and the actual value with respect to time, and d is the composite disturbance of the control system.

[0028] As a preferred solution of the longitudinal and lateral control method of the port intelligent horizontal transport vehicle of the present invention, the sliding mode controller of the port intelligent horizontal transport vehicle lateral control system is designed, according to the physical constraints of the steering mechanism of the port intelligent horizontal transport vehicle, to limit the control amount of the front and rear wheel angles of the port intelligent horizontal transport vehicle as follows:

[0029]

[0030] Finally, the control quantity of the sliding mode controller of the lateral control system of the port intelligent horizontal transport vehicle is expressed as:

[0031]

[0032] As a preferred solution of the longitudinal and lateral control method of the port intelligent horizontal transport vehicle described in the present invention, wherein: according to the actual operating conditions of the port intelligent horizontal transport vehicle, a longitudinal and lateral control system of the port intelligent horizontal transport vehicle is constructed, wherein the design of the longitudinal control system of the port intelligent horizontal transport vehicle is mainly through adjusting the longitudinal acceleration, and the first-order inertial system of the longitudinal control system is expressed as:

[0033]

[0034] in, is the rate of change of longitudinal acceleration, τ d is the time constant, a des and a are the target value and actual value of the longitudinal acceleration of the port intelligent horizontal transport vehicle, respectively;

[0035] Considering the longitudinal system disturbance, the longitudinal control system of the port intelligent horizontal transport vehicle is expressed as a state equation:

[0036]

[0037] As a preferred solution of the longitudinal and transverse control method of the port intelligent horizontal transport vehicle of the present invention, the sliding mode controller of the longitudinal control system of the port intelligent horizontal transport vehicle is designed to limit the longitudinal acceleration control amount of the port intelligent horizontal transport vehicle as follows according to the operation characteristics of the port intelligent horizontal transport vehicle:

[0038]

[0039] Finally, the control quantity of the sliding mode controller of the longitudinal control system of the port intelligent horizontal transport vehicle is expressed as:

[0040]

[0041] In a second aspect, the present invention provides a longitudinal and transverse control system for a port intelligent horizontal transport vehicle, comprising:

[0042] Establish a module, and establish a lateral two-degree-of-freedom single-track dynamic model of the port intelligent horizontal transportation vehicle by uniformly setting the system performance of the port intelligent horizontal transportation vehicle;

[0043] The construction module builds the lateral and longitudinal control system of the port intelligent horizontal transport vehicle according to the actual operating conditions of the port intelligent horizontal transport vehicle;

[0044] A design module is provided, and based on the transverse and longitudinal control systems of the port intelligent horizontal transport vehicles, the disturbance observer and the corresponding sliding mode controller in the transverse and longitudinal control systems are respectively designed to realize the hierarchical decoupling control of the vehicle.

[0045] In a third aspect, the present invention provides a computing device, comprising:

[0046] Memory, used to store programs;

[0047] The processor is used to execute the computer executable instructions, which, when executed by the processor, implement the steps of the longitudinal and transverse control method of the port intelligent horizontal transport vehicle.

[0048] In a fourth aspect, the present invention provides a computer-readable storage medium, comprising: when the program is executed by a processor, the steps of implementing the longitudinal and lateral control method of the port intelligent horizontal transport vehicle.

[0049] Beneficial effects of the present invention: The present invention respectively designs a disturbance observer and a corresponding sliding mode controller for the lateral and longitudinal control systems of the port intelligent horizontal transport vehicles to realize hierarchical decoupling control of the vehicle. The drivable area of ​​the port intelligent horizontal transport vehicles at the container terminal is limited and the external environment is complex and changeable. Executing lateral and longitudinal hierarchical control of the vehicles can significantly improve the system robustness, driving safety, control accuracy and container transshipment efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0051] Figure 1 A basic flow chart of a method for controlling the longitudinal and transverse directions of a port intelligent horizontal transport vehicle provided by one embodiment of the present invention;

[0052] Figure 2 A block diagram of a sliding mode control system for a port intelligent horizontal transport vehicle based on a disturbance observer, which is a longitudinal and lateral control method for a port intelligent horizontal transport vehicle provided by one embodiment of the present invention;

[0053] Figure 3 A diagram of a single-track dynamics model of a port intelligent horizontal transport vehicle according to a longitudinal and transverse control method of a port intelligent horizontal transport vehicle provided by one embodiment of the present invention;

[0054] Figure 4 A comparison diagram of path tracking data of a port intelligent horizontal transport vehicle according to a longitudinal and transverse control method of a port intelligent horizontal transport vehicle provided by one embodiment of the present invention;

[0055] Figure 5 A comparison diagram of front wheel turning angle data of a port intelligent horizontal transport vehicle according to a longitudinal and lateral control method of a port intelligent horizontal transport vehicle provided by one embodiment of the present invention;

[0056] Figure 6 A comparison diagram of heading angle data of a port intelligent horizontal transport vehicle according to a longitudinal and transverse control method of a port intelligent horizontal transport vehicle provided by one embodiment of the present invention;

[0057] Figure 7 A comparison diagram of longitudinal speed data of a port intelligent horizontal transport vehicle according to a longitudinal and transverse control method of a port intelligent horizontal transport vehicle provided by one embodiment of the present invention;

[0058] Figure 8 A comparison diagram of lateral / longitudinal disturbance observer data for a longitudinal and lateral control method for a port intelligent horizontal transport vehicle provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0059] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0060] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0061] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0062] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0063] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0064] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0065] Example 1

[0066] Reference Figure 1-Figure 3 , is an embodiment of the present invention, which provides a longitudinal and lateral control method for a port intelligent horizontal transport vehicle, such as Figure 1 As shown, the following steps are included:

[0067] S1: By uniformly setting the system performance of the port intelligent horizontal transport vehicle, a lateral two-degree-of-freedom single-track dynamic model of the port intelligent horizontal transport vehicle is established;

[0068] Furthermore, the sliding mode control strategy based on the disturbance observer; the control method based on the observer originates from engineering practice. Its core idea is to predict or estimate the system disturbance by designing a reasonable observer, and use the estimated value of the disturbance as feedforward compensation, and solve the control system input in combination with the feedback controller to achieve the goal of reducing the influence of the disturbance and improving the control performance of the system. This type of control method has a simple structure and is easy to realize online parameter tuning and engineering application. The relevant control system structure is as follows: Figure 2 shown.

[0069] Furthermore, in order to facilitate problem analysis and controller design, the performance of the port intelligent horizontal transport vehicle system is uniformly set without loss of generality:

[0070] 1) The tire characteristics of the port intelligent horizontal transport vehicles are set to be consistent and there is no self-aligning torque.

[0071] 2) Set the movement state of the wheels on both sides of the coaxial axis of the port intelligent horizontal transport vehicle to be consistent.

[0072] 3) Ignore the rolling and pitching motions of the port’s intelligent horizontal transport vehicles.

[0073] 4) The port’s intelligent horizontal transport vehicles are equipped with independent front and rear wheel steering and front and rear axle drive.

[0074] Based on the above settings, a lateral two-degree-of-freedom single-track dynamic model of the port intelligent horizontal transport vehicle is established, such as Figure 3 XOY is the world coordinate system, xoy is the body coordinate system of the port intelligent horizontal transport vehicle, where o is the location of the center of mass; F xf 、F xr 、F yf 、F yr are the tire longitudinal force and lateral force acting on the front and rear axles of the port intelligent horizontal transport vehicle respectively; δ f and δ r is the front and rear wheel turning angles of the port intelligent horizontal transport vehicle; α f , α r are the front and rear wheel slip angles of the port intelligent horizontal transport vehicle; v x 、v y , β are the longitudinal speed, lateral speed, yaw rate and sideslip angle of the port intelligent horizontal transport vehicle; l f and l r are the distances from the front and rear axles to the center of mass of the port intelligent horizontal transport vehicle. The following dynamic equations of the port intelligent horizontal transport vehicle can be obtained using the Newton-Euler method:

[0075]

[0076] Among them, m is the total mass of the port intelligent horizontal transport vehicle, is the lateral acceleration of the port intelligent horizontal transport vehicle, I z represents the moment of inertia of the port intelligent horizontal transport vehicle around the z-axis, Represents the yaw angular acceleration of the port intelligent horizontal transport vehicle. When the lateral acceleration acting on the tire of the port intelligent horizontal transport vehicle is not greater than 0.4g and the tire slip angle does not exceed 5°, the tire force and tire stiffness can be approximately described as a linear relationship:

[0077]

[0078] Among them, C lf With C lr are the longitudinal stiffness of the front and rear axle tires of the port intelligent horizontal transport vehicle; C cf With C cr are the cornering stiffness of the front and rear axle tires respectively; s f With s r are the slip rates of the front and rear axle tires, respectively.

[0079] Ignore the tire longitudinal force F xf and F xr The influence of yaw motion can be summarized by combining equations (1) and (2) into the two-degree-of-freedom lateral dynamics model of the port intelligent horizontal transport vehicle:

[0080]

[0081] In formula (3), the side slip angles of the front and rear wheels of the port intelligent horizontal transport vehicle are f With α r It can be calculated by formula (4):

[0082]

[0083] Considering the effect of disturbance on the lateral system of the port intelligent horizontal transport vehicle, the two-degree-of-freedom lateral dynamics model of the port intelligent horizontal transport vehicle is rewritten into the form of state equation:

[0084]

[0085] Among them, x is the state quantity of the control system, is the derivative of the control quantity in the time domain. A is the state transfer matrix, B is the input matrix, u is the system control quantity, d is the lateral system interference term. y is the system output quantity, and C is the output matrix.

[0086] S2: Based on the actual operating conditions of the port intelligent horizontal transport vehicles, a lateral and longitudinal control system for the port intelligent horizontal transport vehicles is constructed;

[0087] Furthermore, the lateral control system design of the port intelligent horizontal transport vehicle based on the disturbance observer: The lateral control needs to ensure that the lateral deviation and heading angle deviation of the port intelligent horizontal transport vehicle do not exceed the allowable range of the system during movement. Therefore, the main control parameters of the lateral system are:

[0088]

[0089] Among them, Y e , Y and Y ref are the lateral deviation, actual lateral coordinate and reference lateral coordinate of the port intelligent horizontal transport vehicle in the world coordinate system. and They are respectively the heading angle deviation, actual heading angle and reference heading angle of the port intelligent horizontal transport vehicle in the world coordinate system.

[0090] Furthermore, the longitudinal control system of the port intelligent horizontal transport vehicle is designed based on the disturbance observer: The longitudinal control of the port intelligent horizontal transport vehicle is mainly achieved by adjusting the longitudinal acceleration to improve the driving stability and parking accuracy of the port intelligent horizontal transport vehicle during path tracking. The longitudinal control system can be expressed as a first-order inertial system:

[0091]

[0092] in, is the rate of change of longitudinal acceleration, τ d is the time constant, a des and a are the target value and actual value of the longitudinal acceleration of the port intelligent horizontal transport vehicle, respectively. Considering the longitudinal system disturbance, the longitudinal control system of the port intelligent horizontal transport vehicle is expressed as a state equation:

[0093]

[0094] S3: Based on the transverse and longitudinal control systems of the port intelligent horizontal transport vehicles, the disturbance observer and the corresponding sliding mode controller in the transverse and longitudinal control systems of the port intelligent horizontal transport vehicles are designed respectively to realize the hierarchical decoupling control of the vehicles.

[0095] Furthermore, based on the above system state equation (5), the lateral disturbance observer can be designed as:

[0096]

[0097] in, is the estimated value of the disturbance d, ξ is the intermediate variable, and L represents the observer gain matrix. The disturbance error is defined as:

[0098]

[0099] in, represents the interference error, is the differential of the interference error with respect to time. Similarly, and Represent the differentials of the estimated value and the actual value of the disturbance with respect to time. Assume that the disturbance to the system is slowly time-varying, that is, Combining equations (5), (9), and (10), we can obtain:

[0100]

[0101] Further seek in is a bounded constant. It can be seen that only by selecting a suitable L can the error of the disturbance observer converge exponentially. The proof process is as follows:

[0102] Design of Lyapunov function but Therefore, by selecting a suitable matrix L, the observer can interfere with the estimated value Approximate the actual interference value d in exponential form.

[0103] In order to further simplify the lateral dynamics model of the port intelligent horizontal transport vehicle and facilitate the controller design, a Y e and Nonlinear function of (since the operating speed of the port intelligent horizontal transport vehicle in the terminal usually does not exceed 25km / h, the influence of the center of mass sideslip angle on the system can be ignored):

[0104]

[0105] Among them, the parameters c0 and c1 are both positive numbers and satisfy 0<c0<π, 0<c1<π. Obviously, when z→0, it can be guaranteed that Y e →0, The specific proof process is as follows:

[0106] Design of Lyapunov function And taking the derivative of V, we get

[0107]

[0108] If z→0, then So far, we can analyze three situations The positive and negative properties of Y e <0,0<-c0tanh(c1Y e )<π,sin(-c0tanh(c1Y e ))>0, we can get When Y e>0, -c0<-c0 tanh(c1Y e )<0,sin(-c0 tanh(c1Y e ))<0, we can get Similarly, when Y e =0, we can get In summary It always holds true, that is, when z→0, the lateral error Y of the port intelligent horizontal transport vehicle e and heading angle error will converge to 0, so it is necessary to reasonably control the heading angle of the port intelligent horizontal transport vehicle. To ensure Y e →0.

[0109] Design of lateral sliding mode controller: According to the conclusion obtained in formula (12), the switching function of the lateral sliding mode controller is designed as:

[0110]

[0111] Take the uniform velocity approaching law and let:

[0112]

[0113] In order to weaken the system chattering, a continuous function is used to replace the sign function in equation (14), and then:

[0114]

[0115] Among them, k is a positive real number and δ is a positive decimal. Combining the above formula, the control quantity δ of the lateral sliding mode control system can be obtained: f and δ r ;

[0116] According to the physical constraints of the steering mechanism of the port intelligent horizontal transport vehicle, the control amount of the front and rear wheel steering angles of the port intelligent horizontal transport vehicle is limited as follows:

[0117]

[0118] Finally, the control quantity of the sliding mode controller of the lateral control system of the port intelligent horizontal transport vehicle is expressed as:

[0119]

[0120] Since the design process of the longitudinal disturbance observer is similar to that of the lateral disturbance observer, the relevant steps are omitted here.

[0121] Design of longitudinal sliding mode controller: The error and its derivative of the longitudinal control system of the port intelligent horizontal transport vehicle can be expressed as:

[0122] e=[v ref -varef- a] T =Rx (18)

[0123] Among them, v ref and a ref are the expected longitudinal velocity and acceleration respectively, and R=[v ref a ref ] T .

[0124] The switching function of the longitudinal sliding mode controller is defined as:

[0125] s=Ce+Du (19)

[0126] Where D>0, C=[C(1)C(2)]. When s=0, Du=-Ce. In order to form negative feedback, C<0 here. From formula (20), the first-order derivative of the switching function can be obtained as:

[0127]

[0128] In order to reduce system chattering, the exponential reaching law is adopted, and:

[0129]

[0130] Where sgn is a sign function, and ε and k are both positive real numbers. Combining equations (21) and (22), the longitudinal system dynamic control quantity can be obtained as:

[0131]

[0132] Proof of stability of longitudinal control system: Design of Lyapunov function Further sorting can be obtained ε>0,k>0. Obviously It always holds true, so the control system is asymptotically stable.

[0133] According to the operation characteristics of the port intelligent horizontal transport vehicle, the longitudinal acceleration control amount is limited as follows:

[0134]

[0135] Finally, the control quantity of the sliding mode controller of the longitudinal control system of the port intelligent horizontal transport vehicle is expressed as:

[0136]

[0137] This embodiment also provides a longitudinal and transverse control system for a port intelligent horizontal transport vehicle, comprising:

[0138] Establish a module, and establish a lateral two-degree-of-freedom single-track dynamic model of the port intelligent horizontal transportation vehicle by uniformly setting the system performance of the port intelligent horizontal transportation vehicle;

[0139] The construction module builds the lateral and longitudinal control system of the port intelligent horizontal transport vehicle according to the actual operating conditions of the port intelligent horizontal transport vehicle;

[0140] A design module is provided, and based on the transverse and longitudinal control systems of the port intelligent horizontal transport vehicles, the disturbance observer and the corresponding sliding mode controller in the transverse and longitudinal control systems are respectively designed to realize the hierarchical decoupling control of the vehicle.

[0141] Furthermore, it also includes:

[0142] Memory, used to store programs;

[0143] The processor is used to load the program to execute the longitudinal and transverse control method of the port intelligent horizontal transport vehicle.

[0144] This embodiment also provides a computer-readable storage medium storing a program, which, when executed by a processor, implements the longitudinal and lateral control method of the port intelligent horizontal transport vehicle.

[0145] The storage medium proposed in this embodiment and the longitudinal and lateral control method of the port intelligent horizontal transport vehicle proposed in the above embodiment belong to the same inventive concept. The technical details not described in detail in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0146] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (RandomAccess Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0147] Example 2

[0148] Reference Figure 4-8, which is an embodiment of the present invention, provides a longitudinal and lateral control method for a port intelligent horizontal transport vehicle. In order to verify the effectiveness of the proposed method, comparative experiments are carried out from several aspects including path tracking performance, longitudinal speed jump and interference observation accuracy of the port intelligent horizontal transport vehicle.

[0149] The specific embodiments are as follows:

[0150] Using a vehicle dynamics simulation software and numerical analysis software, a joint simulation of the typical operating conditions of a port intelligent horizontal transport vehicle moving from the yard to the quay crane was conducted. The vehicle model provided by a vehicle dynamics software (similar to the motion performance of a port intelligent horizontal transport vehicle) was used in the simulation, and a hard road surface was selected and the road adhesion coefficient μ = 0.8 was set. In addition, the lateral disturbance observer gain matrix was set to L = -0.15B T , where B is the lateral input matrix. The parameters of the lateral sliding mode controller are set to: c0 = 4.65, c1 = 3.9, k = 3.15, δ = 0.35. The longitudinal disturbance observer gain matrix is ​​set to L = [-20 15], and the parameters of the longitudinal sliding mode controller are set to: C = [-10, -0.25], D = 0.05, ε = 15, k = 0.5. During the simulation, the lateral and longitudinal systems of the port intelligent horizontal transport vehicle are applied respectively. and The simulation time is t = 25s. The relevant experimental results are as follows Figures 4 to 8 shown.

[0151] like Figure 4 As shown in the figure, when there are lateral / longitudinal disturbances in the system, the sliding mode control algorithm based on disturbance observer (DOB_SMC) has higher robustness, error convergence speed and convergence accuracy. The parking accuracy of the port intelligent horizontal transport vehicle is high, which can effectively shorten the alignment time between the lifting equipment of the loading and unloading equipment and the port intelligent horizontal transport vehicle, and significantly improve the efficiency of container loading and unloading. Figure 5 In the simulation, DOB_SMC has stronger anti-disturbance capability than the sliding mode controller (SMC). At the beginning of the simulation, the control amount of the corner of the port intelligent horizontal transport vehicle under the action of SMC has a large jump, and the system has strong vibration during the turning process. However, the output of the corner control amount of DOB_SMC is smoother, which can provide higher safety protection for heavy-load and high-inertia transport equipment such as port intelligent horizontal transport vehicles, reduce the impact on their actuators and containers, and improve the service life of various components of port intelligent horizontal transport vehicles, and ensure the safety of goods in containers.

[0152] like Figure 6As shown in the figure, during the movement of the port intelligent horizontal transport vehicle from the yard to the quay crane, the steering of the port intelligent horizontal transport vehicle is smoother under the action of DOB_SMC. Although SMC itself has a certain robustness, when the system is subject to strong external interference, large vibration will be inevitable, and high error convergence accuracy cannot be guaranteed. DOB_SMC can provide feedforward compensation in time according to changes in external interference, making the port intelligent horizontal transport vehicle run more smoothly and with higher posture accuracy when parking, avoiding the time waste caused by repeated adjustment of the hoisting equipment for loading and unloading. Figure 7 In the experiment, the longitudinal speed tracking performance of the port intelligent horizontal transport vehicle under the action of DOB_SMC is better. On the contrary, the speed jump of the port intelligent horizontal transport vehicle under the action of SMC is more significant within 10-18s, and the vehicle has obvious bumps. In the deceleration stage of 21-25s, the speed of the port intelligent horizontal transport vehicle under the action of DOB_SMC is smoother and the tracking accuracy is higher. The excellent longitudinal speed tracking performance will provide a strong guarantee for the smooth and high-precision parking of the port intelligent horizontal transport vehicle. Figure 8 As shown, the disturbance observer designed in the present invention can estimate the disturbance suffered by the system with high real-time performance and accuracy, and provide effective disturbance compensation for the control system.

[0153] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A longitudinal and transverse control method for a port intelligent horizontal transport vehicle, characterized in that: include: By uniformly setting the system performance of the port intelligent horizontal transport vehicle, a lateral two-degree-of-freedom single-track dynamic model of the port intelligent horizontal transport vehicle is established; According to the actual operating conditions of the port intelligent horizontal transport vehicles, the horizontal and vertical control system of the port intelligent horizontal transport vehicles is constructed; Based on the lateral and longitudinal control systems of the port intelligent horizontal transport vehicles, the disturbance observer and the corresponding sliding mode controller in the lateral and longitudinal control systems of the port intelligent horizontal transport vehicles are designed respectively to realize the hierarchical decoupling control of the vehicles; The method of uniformly setting the performance of the port intelligent horizontal transport vehicle system includes the following steps: The characteristics of the tires of the port intelligent horizontal transport vehicles are set to be consistent and there is no self-aligning torque; Set the wheels on both sides of the coaxial axis of the port intelligent horizontal transport vehicle to move in the same state; Ignore the rolling and pitching motions of the intelligent horizontal transport vehicles in the port; The port intelligent horizontal transport vehicle is configured with independent front and rear wheel steering and front and rear axle drive; The establishment of the lateral two-degree-of-freedom single-track dynamic model of the port intelligent horizontal transportation vehicle includes obtaining the dynamic equation of the port intelligent horizontal transportation vehicle by using the Newton-Euler method: Among them, m is the total mass of the port intelligent horizontal transport vehicle, and is the longitudinal acceleration and lateral acceleration of the port intelligent horizontal transport vehicle, I z represents the moment of inertia of the port intelligent horizontal transport vehicle around the z-axis, represents the yaw angular acceleration of the port intelligent horizontal transport vehicle; F xf 、F xr 、F yf 、F yr are the tire longitudinal force and lateral force acting on the front and rear axles of the port intelligent horizontal transport vehicle respectively; δ f and δ r is the front and rear wheel turning angles of the port intelligent horizontal transport vehicle; α f , α r are the front and rear wheel slip angles of the port intelligent horizontal transport vehicle; v x 、v y , are the longitudinal speed, lateral speed and yaw angular velocity of the port intelligent horizontal transport vehicle respectively; l f and l r are the distances from the front and rear axles to the center of mass of the port’s intelligent horizontal transport vehicle, respectively; When the lateral acceleration acting on the tire of the port intelligent horizontal transport vehicle is no more than 0.4g and the tire slip angle does not exceed 5°, the tire force and tire stiffness are approximately described as a linear relationship: Among them, C lf With C lr are the longitudinal stiffness of the front and rear axle tires of the port intelligent horizontal transport vehicle; C cf With C cr are the cornering stiffness of the front and rear axle tires respectively; s f With s r are the slip rates of the front and rear axle tires, respectively; Ignore the tire longitudinal force F xf and F xr In order to consider the influence of yaw motion, the two-degree-of-freedom lateral dynamics model of the port intelligent horizontal transport vehicle is organized as follows: Side slip angle α of front and rear wheels of intelligent horizontal transport vehicles in ports f With α r The calculation results are: Considering the effect of disturbance on the lateral system of the port intelligent horizontal transport vehicle, the two-degree-of-freedom lateral dynamics model of the port intelligent horizontal transport vehicle is rewritten into the form of state equation: Among them, x is the state quantity of the control system, is the derivative of the control quantity in the time domain, A is the state transfer matrix, B is the input matrix, u is the system control quantity, d is the lateral system interference term, y is the system output, and C is the output matrix; The method of constructing a lateral and longitudinal control system of a port intelligent horizontal transport vehicle according to the actual operating conditions of the port intelligent horizontal transport vehicle comprises the following steps: The lateral control needs to ensure that the lateral deviation and heading angle deviation of the port intelligent horizontal transport vehicle do not exceed the allowable range of the system. The main control parameters of the lateral system are: AND e =YY ref Among them, Y e , Y and Y ref are the lateral deviation, actual lateral coordinate and reference lateral coordinate of the port intelligent horizontal transport vehicle in the world coordinate system, and They are the heading angle deviation, actual heading angle and reference heading angle of the port intelligent horizontal transport vehicle in the world coordinate system; The longitudinal control of the port intelligent horizontal transport vehicle is achieved by adjusting the longitudinal acceleration. The longitudinal control system is expressed as a first-order inertial system: in, is the rate of change of longitudinal acceleration, τ d is the time constant, a des and a are the target value and actual value of the longitudinal acceleration of the port intelligent horizontal transport vehicle, respectively; Considering the longitudinal system disturbance, the longitudinal control system of the port intelligent horizontal transport vehicle is expressed as a state equation: The method of designing the disturbance observer and the corresponding sliding mode controller in the lateral and longitudinal control system of the port intelligent horizontal transport vehicle based on the lateral and longitudinal control system of the port intelligent horizontal transport vehicle respectively comprises the following steps: The lateral disturbance observer is designed as: in, is the estimated value of the disturbance d, ξ is the intermediate variable, and L represents the observer gain matrix; The interference error is defined as: in, represents the interference error, is the time derivative of the disturbance error, and Represent the differentials of the estimated and actual values ​​of interference with respect to time, respectively; Assume that the disturbance to the system is slowly time-varying, that is The following formula is obtained: Further seek in is a bounded constant; select a suitable matrix L to prove the process as follows: Design of Lyapunov function but Design the switching function of the lateral sliding mode controller as: Take the uniform velocity approaching law and let: Using a continuous function to replace the symbolic function sgn(s) in the original expression, we have: Among them, k is a positive real number, δ is a positive decimal, and the control quantity δ of the lateral sliding mode control system is obtained f and δ r ; According to the physical constraints of the steering mechanism of the port intelligent horizontal transport vehicle, the control amount of the front and rear wheel steering angles of the port intelligent horizontal transport vehicle is limited as follows: Finally, the control quantity of the sliding mode controller of the lateral control system of the port intelligent horizontal transport vehicle is expressed as The design process of the longitudinal disturbance observer is the same as that of the lateral disturbance observer; The longitudinal control system error and its derivative of the port intelligent horizontal transport vehicle are expressed as: e=[v ref -v a ref -a] T =R-x Among them, v ref and a ref are the expected longitudinal velocity and acceleration respectively, and R=[v ref a ref ] T ; The switching function of the longitudinal sliding mode controller is defined as: s=Ce+Du Where D>0, C=[C(1)C(2)], when s=0, Du=-Ce, C<0; The first-order derivative of the switching function is obtained as: Using the exponential reaching law, let: Among them, sgn is the sign function, ε and k are both positive real numbers; The longitudinal system dynamic control quantity is obtained as: Design of Lyapunov function Arranged According to the operation characteristics of the port intelligent horizontal transport vehicle, the longitudinal acceleration control amount is limited as follows: Finally, the control quantity of the sliding mode controller of the longitudinal control system of the port intelligent horizontal transport vehicle is expressed as:

2. A control system based on the longitudinal and transverse control method of the port intelligent horizontal transport vehicle according to claim 1, characterized in that: Establish a module, and establish a lateral two-degree-of-freedom single-track dynamic model of the port intelligent horizontal transportation vehicle by uniformly setting the system performance of the port intelligent horizontal transportation vehicle; The construction module builds the lateral and longitudinal control system of the port intelligent horizontal transport vehicle according to the actual operating conditions of the port intelligent horizontal transport vehicle; Design module, based on the lateral and longitudinal control system of the port intelligent horizontal transport vehicle, respectively design the disturbance observer and the corresponding sliding mode controller in the lateral and longitudinal control system of the port intelligent horizontal transport vehicle to realize the hierarchical decoupling control of the vehicle; A setting module is used to set the characteristics of each tire of the port intelligent horizontal transport vehicle to be consistent and without a return torque; Set the wheels on both sides of the coaxial axis of the port intelligent horizontal transport vehicle to move in the same state; Ignore the rolling and pitching motions of the intelligent horizontal transport vehicles in the port; The port intelligent horizontal transport vehicle is configured with independent front and rear wheel steering and front and rear axle drive; The calculation module is used to obtain the dynamic equations of the port intelligent horizontal transport vehicle using the Newton-Euler method: Among them, m is the total mass of the port intelligent horizontal transport vehicle, and is the longitudinal acceleration and lateral acceleration of the port intelligent horizontal transport vehicle, I z represents the moment of inertia of the port intelligent horizontal transport vehicle around the z-axis, represents the yaw angular acceleration of the port intelligent horizontal transport vehicle; F xf 、F xr 、F yf 、F yr are the tire longitudinal force and lateral force acting on the front and rear axles of the port intelligent horizontal transport vehicle respectively; δ f and δ r is the front and rear wheel turning angles of the port intelligent horizontal transport vehicle; α f , α r are the front and rear wheel slip angles of the port intelligent horizontal transport vehicle; v x 、v y , are the longitudinal speed, lateral speed and yaw angular velocity of the port intelligent horizontal transport vehicle respectively; l f and l r are the distances from the front and rear axles to the center of mass of the port’s intelligent horizontal transport vehicle, respectively; When the lateral acceleration acting on the tire of the port intelligent horizontal transport vehicle is no more than 0.4g and the tire slip angle does not exceed 5°, the tire force and tire stiffness are approximately described as a linear relationship: Among them, C lf With C lr are the longitudinal stiffness of the front and rear axle tires of the port intelligent horizontal transport vehicle; C cf With C cr are the cornering stiffness of the front and rear axle tires respectively; s f With s r are the slip rates of the front and rear axle tires, respectively; Ignore the tire longitudinal force F xf and F xr In order to consider the influence of yaw motion, the two-degree-of-freedom lateral dynamics model of the port intelligent horizontal transport vehicle is organized as follows: Side slip angle α of front and rear wheels of intelligent horizontal transport vehicles in ports f With α r The calculation results are: Considering the effect of disturbance on the lateral system of the port intelligent horizontal transport vehicle, the two-degree-of-freedom lateral dynamics model of the port intelligent horizontal transport vehicle is rewritten into the form of state equation: Among them, x is the state quantity of the control system, is the derivative of the control quantity in the time domain, A is the state transfer matrix, B is the input matrix, u is the system control quantity, d is the lateral system interference term, y is the system output, and C is the output matrix; The lateral control needs to ensure that the lateral deviation and heading angle deviation of the port intelligent horizontal transport vehicle do not exceed the allowable range of the system. The main control parameters of the lateral system are: AND e =YY ref Among them, Y e , Y and Y ref are the lateral deviation, actual lateral coordinate and reference lateral coordinate of the port intelligent horizontal transport vehicle in the world coordinate system, and They are the heading angle deviation, actual heading angle and reference heading angle of the port intelligent horizontal transport vehicle in the world coordinate system; The regulation module is used for the longitudinal control of the intelligent horizontal transport vehicle in the port. By adjusting the longitudinal acceleration, the longitudinal control system is expressed as a first-order inertial system: in, is the rate of change of longitudinal acceleration, τ d is the time constant, a des and a are the target value and actual value of the longitudinal acceleration of the port intelligent horizontal transport vehicle, respectively; Considering the longitudinal system disturbance, the longitudinal control system of the port intelligent horizontal transport vehicle is expressed as a state equation: The lateral disturbance observer design module is used to design the lateral disturbance observer as: in, is the estimated value of the disturbance d, ξ is the intermediate variable, and L represents the observer gain matrix; The interference error is defined as: in, represents the interference error, is the time derivative of the disturbance error, and Represent the differentials of the estimated and actual values ​​of interference with respect to time, respectively; Assume that the disturbance to the system is slowly time-varying, that is The following formula is obtained: Further seek in is a bounded constant; select a suitable matrix L to prove the process as follows: Design of Lyapunov function but Design the switching function of the lateral sliding mode controller as: Take the uniform velocity approaching law and let: Using a continuous function to replace the symbolic function sgn(s) in the original expression, we have: Among them, k is a positive real number, δ is a positive decimal, and the control quantity δ of the lateral sliding mode control system is obtained f and δ r ; According to the physical constraints of the steering mechanism of the port intelligent horizontal transport vehicle, the control amount of the front and rear wheel steering angles of the port intelligent horizontal transport vehicle is limited as follows: Finally, the control quantity of the sliding mode controller of the lateral control system of the port intelligent horizontal transport vehicle is expressed as The design process of the longitudinal disturbance observer is the same as that of the lateral disturbance observer; The longitudinal control system error and its derivative of the port intelligent horizontal transport vehicle are expressed as: e=[v ref -v a ref -a] T =R-x Among them, v ref and a ref are the expected longitudinal velocity and acceleration respectively, and R=[v ref a ref ] T ; The switching function of the longitudinal sliding mode controller is defined as: s=Ce+Du Where D>0, C=[C(1)C(2)], when s=0, Du=-Ce, C<0; The first-order derivative of the switching function is obtained as: Using the exponential reaching law, let: Among them, sgn is the sign function, ε and k are both positive real numbers; The longitudinal system dynamic control quantity is obtained as: Design of Lyapunov function Arranged According to the operation characteristics of the port intelligent horizontal transport vehicle, the longitudinal acceleration control amount is limited as follows: Finally, the control quantity of the sliding mode controller of the longitudinal control system of the port intelligent horizontal transport vehicle is expressed as:

3. An electronic device, characterized in that: include: Memory, used to store programs; A processor is used to load the program to execute the steps of the longitudinal and transverse control method of the port intelligent horizontal transport vehicle as described in claim 1.

4. A computer-readable storage medium storing a program, characterized in that: When the program is executed by the processor, the steps of the longitudinal and transverse control method of the port intelligent horizontal transport vehicle as claimed in claim 1 are implemented.

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