Method and device for torque coordination control of multi-drive wheels of a planetary rover

Abstract

The present invention provides a method and device for torque coordination control of multiple driving wheels of a planetary rover, relating to the field of intelligent control of planetary rovers. The method includes: obtaining a quasi-static mechanical model; obtaining a linear model of the equivalent concentrated force of a single wheel according to the quasi-static mechanical model; obtaining the current pose and preset speed of the planetary rover; obtaining the desired longitudinal force and desired yaw moment based on the sliding mode theory according to the current pose and the preset speed; obtaining the sum of the hitch traction forces of the unilateral wheels according to the desired longitudinal force and the desired yaw moment; obtaining the self-constraint index of the planetary rover; and coordinately controlling the driving torques of multiple wheels of the planetary rover according to the linear model of the equivalent concentrated force of a single wheel, the sum of the hitch traction forces of the unilateral wheels, and the self-constraint index. Compared with the prior art, the present invention solves the problems of poor motion performance and low safety of the planetary rover during the process of planetary exploration.

Description

Technical Field

[0001] The present invention relates to the field of intelligent control of planetary rovers, and more specifically, to a method and device for coordinated control of torques of multiple drive wheels of a planetary rover. Background Art

[0002] In recent years, various countries around the world have successively launched detectors to carry out planetary exploration activities. Wheeled planetary rovers have become the first choice for mobile detectors in complex position environments due to their stable configuration, high drive efficiency, etc. China has also gradually carried out relevant exploration research work, and successfully launched the Yutu-2 lunar rover and the Zhurong Mars rover, whose configuration is a rocker-type six-wheel planetary rover. When a planetary rover enters and exits a crater, it will be in a climbing working condition, with high requirements for traction force, and may encounter dangerous situations such as large subsidence, high slip, and load exceeding the limit value. Therefore, in order to keep the six-wheel planetary rover running in a better state, it is necessary to conduct research on the coordinated control of multiple drive wheels.

[0003] Most of the existing research is based on the single-wheel drive performance to establish the optimization goal of the whole vehicle control, and there is less research on the comprehensive optimization goal of multi-wheel drive. During the movement of a multi-wheel planetary rover, the force states of each wheel are different and coupled with each other, which poses new challenges to the design of control strategies and control algorithms. Therefore, it is necessary to design a method for coordinated control of torques of multiple drive wheels of a planetary rover to solve the above technical problems. Summary of the Invention

[0004] The problem solved by the present invention is how to coordinate the control of torques of multiple drive wheels of a planetary rover, improve the running performance of the planetary rover, and provide safety guarantee for the planetary rover during the planetary exploration process.

[0005] To solve the above problems, the present invention provides a method for coordinated control of torques of multiple drive wheels of a planetary rover, including the following steps:

[0006] Obtain a quasi-static mechanical model;

[0007] According to the quasi-static mechanical model, obtain an equivalent concentrated force linear model of a single wheel;

[0008] Obtain the current pose and preset speed of the planetary rover;

[0009] According to the current pose and the preset speed, obtain an expected longitudinal force and an expected yaw moment based on the sliding mode theory;

[0010] According to the expected longitudinal force and the expected yaw moment, obtain the sum of the hitch traction forces of the unilateral wheels;

[0011] Obtain the self-constraint index of the planetary rover;

[0012] Based on the equivalent concentrated force linear model of the single wheel, the sum of the drawbar pull forces of the unilateral wheels, and the self-constraint index, the multi-wheel driving torques of the planetary rover are coordinately controlled.

[0013] Optionally, the quasi-static mechanical model includes a stress integral model and a single-wheel analytical decoupling model. Based on the quasi-static mechanical model, obtaining the equivalent concentrated force linear model of the single wheel specifically includes:

[0014] According to the stress integral model, obtain the single-wheel analytical decoupling model;

[0015] According to the single-wheel analytical decoupling model, obtain the equivalent concentrated force linear model of the single wheel.

[0016] Optionally, the obtaining of the single-wheel analytical decoupling model according to the stress integral model specifically includes:

[0017] When the slip ratio of the planetary rover wheel is within a preset range, simplify the stress integral model to obtain the single-wheel analytical decoupling model.

[0018] Optionally, before obtaining the equivalent concentrated force linear model of the single wheel according to the single-wheel analytical decoupling model, it includes:

[0019] Based on the principle of force system equivalence, equivalent the continuously distributed stress to the drawbar pull force in the horizontal direction and the normal force in the vertical direction;

[0020] Obtain the drag force at the wheel axle of the planetary rover and the normal load at the wheel axle of the planetary rover;

[0021] According to the drawbar pull force and the drag force, obtain the first couple moment;

[0022] According to the normal force and the normal load, obtain the second couple moment;

[0023] Obtain the driving torque at the wheel axle of the planetary rover;

[0024] According to the first couple moment, the second couple moment, and the driving torque, obtain the first balance equation.

[0025] Optionally, the obtaining of the equivalent concentrated force linear model of the single wheel according to the single-wheel analytical decoupling model specifically includes:

[0026] According to the single-wheel analytical decoupling model and the first balance equation, obtain the vertical offset and the horizontal offset;

[0027] According to the linear correlation degree between parameters, simplify the vertical offset to the wheel radius, and simplify the horizontal offset to obtain the linear model of the horizontal offset;

[0028] Among them, the wheel radius is the equivalent wheel radius of the wheel spike effect.

[0029] Optionally, obtaining the desired longitudinal force and the desired yaw moment based on the sliding mode theory according to the current pose and the preset speed specifically includes:

[0030] Obtaining the actual speed of the planetary rover according to the current pose;

[0031] Based on the tracking error between the actual speed and the preset speed, obtaining the desired longitudinal force and the desired yaw moment based on the sliding mode theory.

[0032] Optionally, obtaining the actual speed of the planetary rover according to the current pose specifically includes:

[0033] Constructing a dynamic model of the planetary rover with disturbance terms according to the current pose;

[0034] Obtaining the target control force and the target torque;

[0035] Obtaining the actual speed according to the target control force, the target torque and the dynamic model of the planetary rover;

[0036] Among them, the target control force is the resultant force generated by the wheel hitch traction force of the planetary rover in the planetary rover, and the target torque is the yaw moment generated by the wheel hitch traction force of the planetary rover in the planetary rover.

[0037] Optionally, obtaining the desired longitudinal force and the desired yaw moment based on the sliding mode theory according to the tracking error between the actual speed and the preset speed specifically includes:

[0038] Obtaining a preset saturation function approaching rate;

[0039] Based on the tracking error between the actual speed and the preset speed and the approaching rate of the preset saturation function, obtaining the desired longitudinal force and the desired yaw moment.

[0040] Optionally, obtaining the self-constraint index of the planetary rover specifically includes:

[0041] Obtaining the energy efficiency index of the whole vehicle system of the planetary rover, the rocker arm torque balance equation and the wheel torque limit of the planetary rover;

[0042] Based on the energy efficiency index, the rocker arm torque balance equation, the wheel torque limit, the quasi-static mechanical model and the dynamic model of the planetary rover, obtaining the self-constraint index;

[0043] Among them, the self-constraint index is the minimum value of the energy efficiency index.

[0044] The advantages of the multi-drive-wheel torque coordination control method for the planetary rover described in the present invention over the prior art are as follows: The present invention provides a multi-drive-wheel torque coordination control method for the planetary rover. Based on the principle of force system equivalence, the wheel-ground interaction of a single wheel is simplified into an equivalent concentrated force model, providing a theoretical basis for multi-wheel coordination control. Based on the optimization goal of multi-drive-wheel coordination control, the torques of multiple drive wheels are coordinately distributed and controlled, enabling the vehicle to achieve the best driving performance, improving the motion characteristics of the planetary rover, and providing safety guarantees for the planetary rover to perform tasks.

[0045] To solve the above technical problems, the present invention also provides a multi-drive-wheel torque coordination control device for a planetary rover, including:

[0046] An acquisition unit, which is used to acquire a quasi-static mechanical model;

[0047] The acquisition unit is also used to acquire the current pose and preset speed of the planetary rover;

[0048] The acquisition unit is also used to acquire the self-constraint index of the planetary rover;

[0049] A processing unit, which is used to obtain an equivalent concentrated force linear model of a single wheel according to the quasi-static mechanical model;

[0050] The processing unit is also used to obtain the desired longitudinal force and desired yaw moment based on the sliding mode theory according to the current pose and the preset speed;

[0051] The processing unit is also used to obtain the sum of the hitch traction forces of the unilateral wheels according to the desired longitudinal force and the desired yaw moment;

[0052] A control unit, which is used to coordinately control the multi-wheel driving torques of the planetary rover according to the equivalent concentrated force linear model of a single wheel, the sum of the hitch traction forces of the unilateral wheels, and the self-constraint index.

[0053] The advantages of the multi-drive-wheel torque coordination control device for the planetary rover described in the present invention are the same as those of the multi-drive-wheel torque coordination control method for the planetary rover, and will not be elaborated here. Description of the Drawings

[0054] Figure 1 It is an application environment diagram of the multi-drive-wheel torque coordination control method for the planetary rover in an embodiment of the present invention;

[0055] Figure 2 It is a flowchart of the multi-drive-wheel torque coordination control method for the planetary rover in an embodiment of the present invention;

[0056] Figure 3Structural diagram of the multi-drive wheel torque coordination control device for the rover in the embodiment of the present invention;

[0057] Figure 4 Internal structural diagram of the computer device in the embodiment of the present invention. Detailed implementation manners

[0058] Next, the technical solutions in the embodiments of the present application will be described clearly and in detail with reference to the accompanying drawings.

[0059] In the description of the embodiments of the present application, the description of the term "some embodiments" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0060] Figure 1 Application environment diagram of the multi-drive wheel torque coordination control method for the rover in the embodiment of the present application. Refer to Figure 1 , the multi-drive wheel torque coordination control method for the rover is applied to the multi-drive wheel torque coordination control system for the rover. The multi-drive wheel torque coordination control system for the rover includes a terminal 110 and a server 120. The terminal 110 and the server 120 are connected through a network. The terminal 110 may specifically be a desktop terminal or a mobile terminal, and the mobile terminal may specifically be at least one of a mobile phone, a tablet computer, a laptop computer, etc. The server 120 may be implemented by an independent server or a server cluster composed of multiple servers.

[0061] In one embodiment, a multi-drive wheel torque coordination control method for the rover is provided. In this embodiment, it is mainly exemplified that the method is applied to the above Figure 1 terminal 110 (or server 120). Refer to Figure 2 , the multi-drive wheel torque coordination control method for the rover specifically includes the following steps:

[0062] Step S1, obtain a quasi-static mechanical model;

[0063] Step S2, obtain an equivalent concentrated force linear model of a single wheel according to the quasi-static mechanical model;

[0064] Step S3, obtain the current pose and preset speed of the rover;

[0065] Step S4, based on the current pose and the preset speed, obtain an expected longitudinal force and an expected yaw moment based on the sliding mode theory;

[0066] Step S5: Obtain the sum of the hitch traction forces of the single-side wheels according to the expected longitudinal force and the expected yaw moment.

[0067] Step S6: Obtain the self-constraint index of the rover.

[0068] Step S7: Coordinate and control the driving torques of multiple wheels of the rover according to the equivalent concentrated force linear model of the single wheel, the sum of the hitch traction forces of the single-side wheels, and the self-constraint index.

[0069] This embodiment provides a method for coordinating the torques of multiple driving wheels of a rover. Based on the principle of force system equivalence, the wheel-ground interaction of a single wheel is simplified into an equivalent concentrated force model, providing a theoretical basis for multi-wheel coordinated control; based on the optimization objective of multi-driving wheel coordinated control, the torques of multiple driving wheels are optimized and distributed to make the vehicle reach the best driving performance, improve the motion characteristics of the rover, and provide safety guarantees for the rover to perform tasks.

[0070] In some embodiments, in step S2, the quasi-static mechanical model includes a stress integration model and a single-wheel analytical decoupling model. Based on the quasi-static mechanical model, obtaining the equivalent concentrated force linear model of a single wheel specifically includes:

[0071] Step S21: Obtain the single-wheel analytical decoupling model according to the stress integration model.

[0072] Step S22: Obtain the equivalent concentrated force linear model of the single wheel according to the single-wheel analytical decoupling model.

[0073] In some embodiments, in step S21, obtaining the single-wheel analytical decoupling model according to the stress integration model specifically includes:

[0074] Step S211: When the slip ratio of the rover wheel is within a preset range, simplify the stress integration model to obtain the single-wheel analytical decoupling model.

[0075] In some preferred embodiments, when the wheel moves in soft lunar soil, there are continuously acting normal stresses and shear stresses distributed between the wheel and the ground;

[0076] The stress integration model is:

[0077]

[0078] The normal stress and the shear stress can be approximately a piecewise linearized distribution. When the wheel slip ratio is less than or equal to 0.6, simplify the stress integration model to obtain the single-wheel analytical decoupling model as:

[0079]

[0080] Among them, F N , F DP , M R are respectively the normal force, the drawbar traction force, and the resistance moment received by the whole wheel. θ1 is the entry angle, θ2 is the departure angle, and θ m is the maximum stress angle. σ and τ are respectively the normal stress and the shear stress of the wheel-ground interaction. r is the wheel radius, and r s is the equivalent wheel radius of the stud effect. K s is the combined settlement modulus, N is the settlement index, σ m is the maximum normal stress of the wheel-ground interaction, and τ m is the maximum shear stress of the wheel-ground interaction.

[0081] In some embodiments, in step S22, before obtaining the equivalent concentrated force linear model of the single wheel according to the single-wheel analytical decoupling model, it further includes:

[0082] Step S221, based on the principle of force system equivalence, equivalent the continuously distributed stress into the drawbar traction force in the horizontal direction and the normal force in the vertical direction;

[0083] Step S222, obtain the drag force at the planet wheel axle and the normal load at the planet wheel axle;

[0084] Step S223, obtain the first couple moment according to the drawbar traction force and the drag force;

[0085] Step S224, obtain the second couple moment according to the normal force and the normal load;

[0086] Step S225, obtain the driving moment at the planet wheel axle;

[0087] Step S226, obtain the first balance equation according to the first couple moment, the second couple moment, and the driving moment.

[0088] In some preferred embodiments, according to the principle of force system equivalence, the continuously distributed stress is equivalent to the drawbar traction force in the horizontal direction and the normal force in the vertical direction. Under quasi-static conditions, the drawbar traction force and the drag force at the wheel axle, and the normal force and the normal load at the wheel axle form two pairs of couples, and the sum of the formed couple moments and the driving moment at the wheel axle is the first balance equation. The first balance equation is:

[0089]

[0090] Among them, l is the vertical offset of the drawbar traction force F DP from the wheel axle, e is the horizontal offset of the normal force F N from the wheel axle, the driving moment T given by the wheel axle motor to the wheel, and the drag force F R at the wheel axle of the wheel., where W is the normal load at the wheel axle.

[0091] In some embodiments, in step S22, according to the single-wheel analytical decoupling model, obtaining the equivalent concentrated force linear model of the single wheel specifically includes:

[0092] Step S227, obtaining the vertical offset and the horizontal offset according to the single-wheel analytical decoupling model and the first balance equation;

[0093] Step S228, simplifying the vertical offset to the wheel radius according to the linear correlation degree between parameters, and simplifying the horizontal offset to obtain the linear model of the horizontal offset;

[0094] Wherein, the wheel radius is the equivalent wheel radius of the stud effect.

[0095] In some preferred embodiments, based on the single-wheel analytical decoupling model and the balance equation of the sum of the couple moments and the driving moment at the wheel axle, the expressions of the vertical offset and the horizontal offset are determined:

[0096]

[0097] Performing polynomial approximation on the expressions of the vertical offset and the horizontal offset to obtain the following expressions:

[0098]

[0099] According to the linear correlation degree between parameters, the vertical offset of the equivalent concentrated force is approximately equal to the equivalent wheel radius of the stud effect, and the horizontal offset e can be represented by the following linear model:

[0100]

[0101] Wherein, k1, k2 and B are the coefficients of the linear model.

[0102] In this embodiment, according to the quasi-static mechanical model, the distribution law of the normal load changing with the concentrated force offset can be obtained. The distribution law is: due to the influence of the concentrated force offset, the lever arm lengths of the normal forces of the front, middle and rear wheels change, and the additional lever arm generated by the hitch traction force further affects the moment balance of the suspension. To maintain the moment balance, the normal loads of the front and middle wheels decrease, and the normal load of the rear wheel increases;

[0103] In this embodiment, according to the quasi-static mechanical model, the variation laws of the driving torques of each wheel of the lunar rover and the power of the whole lunar rover can also be obtained. The distribution laws are as follows: the change of the front wheel slip ratio has an obvious influence on the distribution of the normal loads of each wheel. When the front wheel slip ratio remains unchanged, the change of the slip ratios of the middle and rear wheels has little influence; the magnitude of the resistance and the different speed ratios have a great influence on the distribution of the normal loads; there are obvious differences in the resistance torques of each wheel, and the resistance torque of the rear wheel is larger, but the power of the whole vehicle takes the minimum value when approaching a constant speed.

[0104] In some embodiments, in step S4, according to the current pose and the preset speed, the desired longitudinal force and the desired yaw moment are obtained based on the sliding mode theory, which specifically includes:

[0105] Step S41, according to the current pose, obtain the actual speed of the lunar rover;

[0106] Step S42, based on the tracking error between the actual speed and the preset speed, obtain the desired longitudinal force and the desired yaw moment based on the sliding mode theory.

[0107] In some embodiments, in step S41, according to the current pose, obtaining the actual speed of the lunar rover specifically includes:

[0108] Step S411, according to the current pose, construct a dynamic model of the lunar rover with disturbance terms;

[0109] Step S412, obtain the target control force and the target moment;

[0110] Step S413, according to the target control force, the target moment and the dynamic model of the lunar rover, obtain the actual speed;

[0111] Wherein, the target control force is the resultant force generated by the wheel hitch traction force of the lunar rover in the lunar rover, and the target moment is the yaw moment generated by the wheel hitch traction force of the lunar rover in the lunar rover.

[0112] In some preferred embodiments, when the lunar rover moves on a rough terrain, according to the current pose, the dynamic equation of the lunar rover with disturbance terms is constructed as:

[0113]

[0114] Taking the resultant force and the yaw moment generated by the wheel hitch traction force in the lunar rover as the target control force and the target moment, the following formula is obtained:

[0115]

[0116] According to the target control force and the target torque, the dynamic equation of the planetary rover is rewritten to obtain the actual velocity as follows:

[0117]

[0118] Wherein, is the first derivative of the longitudinal velocity, ω r is the yaw angular velocity, v y is the lateral velocity, is the hitch traction force of each wheel, ξ x , ξ z are the uncertain terms caused by factors such as rough terrain interference, I z is the moment of inertia about the z-axis, L W is the distance between the hitch traction force and the vehicle's center of mass, L H is the distance between the wheel center of the middle wheel and the vehicle's center of mass.

[0119] In some embodiments, in step S42, according to the tracking error between the actual velocity and the preset velocity, the desired longitudinal force and the desired yaw moment are obtained based on the sliding mode theory, specifically including:

[0120] Step S421, obtain the preset saturation function approaching rate;

[0121] Step S422, according to the tracking error between the actual velocity and the preset velocity and the approaching rate of the preset saturation function, obtain the desired longitudinal force and the desired yaw moment.

[0122] In some preferred embodiments, the preset saturation function approaching rate is:

[0123]

[0124] Track the longitudinal velocity and the yaw angular velocity, denote the desired longitudinal velocity as v xd , and the desired yaw angular velocity as ω rd , then the tracking errors of the longitudinal velocity and the yaw angular velocity are e v and e ω respectively:

[0125] e v = v x - v xd

[0126] e ω = ω r - ω rd ;

[0127] According to the difference between the actual velocity and the set velocity and the approaching rate of the preset saturation function, the desired longitudinal force and the desired yaw moment are obtained as:

[0128]

[0129] In some embodiments, in step S5, according to the expected longitudinal force and the expected yaw moment, the sum of the expected hitch traction forces on both sides of the planetary rover is obtained;

[0130]

[0131] The sum of the expected hitch traction forces on both sides of the planetary rover is used as a constraint condition for lower-layer moment coordinated distribution.

[0132] In some embodiments, in step S6, the self-constraint index of the planetary rover is obtained, specifically including:

[0133] Step S61, obtaining the energy efficiency index of the entire vehicle system of the planetary rover, the rocker arm moment balance equation, and the wheel torque limit of the planetary rover;

[0134] Step S62, according to the energy efficiency index, the rocker arm moment balance equation, the wheel torque limit, the quasi-static mechanical model, and the dynamic model of the planetary rover, the self-constraint index is obtained;

[0135] Wherein, the self-constraint index is the minimum value of the energy efficiency index.

[0136] In some preferred embodiments, the minimum value of the energy efficiency index of the entire vehicle system is used as the optimization objective:

[0137]

[0138] Where T i is the driving torque of each wheel, s i is the slip ratio of each wheel, ω i is the rotational speed of each wheel, v i is the speed of each wheel, r s / is the equivalent wheel radius.

[0139] Based on the rocker arm moment balance equation and the wheel-ground mechanics related model, combined with the torque limit of the wheels, the constraint conditions of the optimization problem are constituted:

[0140]

[0141] Wherein, is the normal force of each wheel, T i is the driving torque of each wheel, is the resistance torque of each wheel;

[0142] h1 and h2 are two equality constraints obtained according to the moment equation of the entire vehicle:

[0143]

[0144] In some preferred embodiments, the sequential quadratic programming algorithm is used to solve for the optimal torque of each wheel, and the error is iteratively approximated; for the initial value of the iterative calculation, the normal load of each wheel at the same slip ratio is used.

[0145] In this embodiment, experimental verification is carried out on the torque coordination control method for the multi-drive wheels of the lunar rover. Specifically, by utilizing the characteristics of the independent drive of the six-wheel lunar rover's multi-drive wheels, different ratios of slip ratios are constructed to verify the single-wheel equivalent concentrated force model, as well as the influence of slip ratio distribution and resistance magnitude on the normal load distribution of the whole vehicle; the torque coordination control method for rough terrain is verified, and compared with the conventional constant-speed motion of each wheel in terms of speed tracking, energy consumption optimization, anti-sinking, and anti-overload.

[0146] Among them, experiments on the mechanical model and torque coordination control are carried out. By changing the rotational speeds of each wheel, the front, middle, and rear wheels are respectively operated at different slip ratios, and their horizontal offset and vertical offset are detected, proving the effectiveness of the single-wheel equivalent concentrated force model and its adaptability in wheels with different loads; two different resistance magnitudes are selected, the rotational speed ratios of each wheel are changed, the forces on each wheel are detected, and the experimental data is compared with the theoretical model, with a small error, proving the accuracy of the mechanical model; the dynamic control and constant-speed motion under different resistances are compared, and the trend is the same as the simulation test results. In terms of the optimization of the energy efficiency index, the torque coordination mode has a certain optimization effect compared with the constant-speed motion mode during the actual motion process; as the torque of the rear wheel decreases, the sinking amount of the rear wheel decreases and the safety increases.

[0147] This embodiment provides a torque coordination control method for the multi-drive wheels of the lunar rover. Based on the principle of force system equivalence, the wheel-ground interaction of a single wheel is simplified into an equivalent concentrated force model, providing a theoretical basis for multi-wheel coordination control; based on the optimization objective of multi-drive wheel coordination control, the torques of the multi-drive wheels are optimized and distributed to make the whole vehicle achieve the best driving performance, improve the motion characteristics of the lunar rover, and provide safety guarantees for the lunar rover to perform tasks.

[0148] As Figure 3 shown, in one embodiment, a torque coordination control device for the multi-drive wheels of the lunar rover is provided, including:

[0149] An acquisition unit 310, where the acquisition unit 310 is used to acquire a quasi-static mechanical model;

[0150] The acquisition unit 310 is further used to acquire the current pose and preset speed of the lunar rover;

[0151] The acquisition unit 310 is further used to acquire the self-constraint index of the lunar rover;

[0152] A processing unit 320, which is configured to obtain an equivalent concentrated force linear model of a single wheel according to the quasi-static mechanical model;

[0153] The processing unit 320 is configured to obtain a desired longitudinal force and a desired yaw moment based on the sliding mode theory according to the current pose and the preset speed;

[0154] The processing unit 320 is configured to obtain the sum of the hitch traction forces of the unilateral wheels according to the desired longitudinal force and the desired yaw moment;

[0155] A control unit 330, which is configured to coordinately control the multi-wheel driving torques of the rover according to the equivalent concentrated force linear model of the single wheel, the sum of the hitch traction forces of the unilateral wheels, and the self-constraint index.

[0156] The acquisition unit 310 in this embodiment is further configured to acquire the energy efficiency index of the rover vehicle system, the rocker arm moment balance equation, and the wheel torque limit of the rover; obtain the self-constraint index according to the energy efficiency index, the rocker arm moment balance equation, the wheel torque limit, the quasi-static mechanical model, and the rover dynamics model; wherein, the self-constraint index is the minimum value of the energy efficiency index;

[0157] The processing unit 320 in this embodiment is further configured to obtain the single-wheel analytical decoupling model according to the stress integral model; and obtain the equivalent concentrated force linear model of the single wheel according to the single-wheel analytical decoupling model;

[0158] The processing unit 320 in this embodiment is further configured to obtain the actual speed of the rover according to the current pose; and obtain the desired longitudinal force and the desired yaw moment based on the sliding mode theory according to the tracking error between the actual speed and the preset speed.

[0159] The multi-wheel driving torque coordination control device of the rover and the multi-drive wheel torque coordination control method of the rover according to the present invention have the same advantages as the prior art, which will not be elaborated herein.

[0160] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned multi-drive wheel torque coordination control method of the rover are implemented.

[0161] Figure 4 The internal structure diagram of the computer device in one embodiment is shown. The computer device may specifically be Figure 1 the terminal 110 (or the server 120) in. As Figure 4As shown, the computer device includes a processor, a memory, a network interface, an input device, and a display screen connected via a system bus. Among them, the memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and may also store a computer program. When the computer program is executed by the processor, the processor can implement the underwater simultaneous localization and mapping method for the underwater robot. The internal memory may also store a computer program. When the computer program is executed by the processor, the processor can execute the dynamic graphics generation method. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer covering the display screen, or a button, trackball, or touchpad provided on the housing of the computer device, or an external keyboard, touchpad, or mouse, etc.

[0162] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned multi-drive-wheel torque coordination control method for the planetary rover are implemented.

[0163] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned various methods. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided in the present application can include non-volatile and / or volatile memories. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or an external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0164] Although the present disclosure is disclosed as above, the protection scope of the present disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and these changes and modifications will all fall within the protection scope of the present invention.

Claims

1. A multi-wheel driving torque coordination control method for a planetary rover, characterized in that It includes the following steps: Obtain the quasi-static mechanical model; According to the quasi-static mechanical model, obtain the equivalent concentrated force linear model of a single wheel; Obtain the current pose and preset speed of the planetary rover; According to the current pose, construct a planetary rover dynamics model with disturbance terms, and based on the current pose and the preset speed, obtain the desired longitudinal force and desired yaw moment based on the sliding mode theory; According to the desired longitudinal force and the desired yaw moment, obtain the sum of the hitch traction forces of the unilateral wheels; Obtain the energy efficiency index of the planetary rover vehicle system, the rocker arm moment balance equation, and the wheel torque limit of the planetary rover; According to the energy efficiency index, the rocker arm moment balance equation, the wheel torque limit, the quasi-static mechanical model, and the planetary rover dynamics model, obtain the self-constraint index of the planetary rover, wherein the self-constraint index is the minimum value of the energy efficiency index; According to the equivalent concentrated force linear model of a single wheel, the sum of the hitch traction forces of the unilateral wheels, and the self-constraint index, perform coordinated control on the multi-wheel driving torques of the planetary rover.

2. The multi-wheel driving torque coordination control method for a planet rover according to claim 1, characterized in that The quasi-static mechanical model includes a stress integration model and a single-wheel analytical decoupling model. The obtaining of the equivalent concentrated force linear model of a single wheel according to the quasi-static mechanical model specifically includes: According to the stress integration model, obtain the single-wheel analytical decoupling model; According to the single-wheel analytical decoupling model, obtain the equivalent concentrated force linear model of a single wheel.

3. The multi-wheel driving torque coordination control method for a planetary rover according to claim 2, wherein The obtaining of the single-wheel analytical decoupling model according to the stress integration model specifically includes: When the slip ratio of the planetary rover wheel is within a preset range, simplify the stress integration model to obtain the single-wheel analytical decoupling model.

4. The multi-wheel driving torque coordination control method for a planetary rover according to claim 3, wherein Before obtaining the equivalent concentrated force linear model of a single wheel according to the single-wheel analytical decoupling model, it includes: Based on the principle of force system equivalence, equivalently convert the continuously distributed stress into the hitch traction force in the horizontal direction and the normal force in the vertical direction; Obtain the drag force at the planetary rover wheel axle and the normal load at the planetary rover wheel axle; According to the hitch traction force and the drag force, obtain the first couple moment; According to the normal force and the normal load, obtain the second couple moment; Obtain the driving torque at the planetary rover wheel axle; According to the first couple moment, the second couple moment, and the driving torque, obtain the first balance equation.

5. The multi-wheel driving torque coordination control method for a planetary rover according to claim 4, characterized in that The obtaining of the equivalent concentrated force linear model of a single wheel according to the single-wheel analytical decoupling model specifically includes: According to the single-wheel analytical decoupling model and the first balance equation, obtain the vertical offset and the horizontal offset; According to the linear correlation degree between parameters, simplify the vertical offset to the wheel radius, and simplify the horizontal offset to obtain the linear model of the horizontal offset; wherein the wheel radius is the equivalent wheel radius of the wheel spike effect.

6. The multi-wheel driving torque coordination control method for a planetary rover according to claim 1, characterized in that, The obtaining of the desired longitudinal force and desired yaw moment based on the sliding mode theory according to the current pose and the preset speed specifically includes: According to the current pose, obtain the actual speed of the planetary rover; Based on the tracking error between the actual speed and the preset speed, obtain the desired longitudinal force and the desired yaw moment based on the sliding mode theory.

7. The multi-wheel driving torque coordination control method for a planetary rover according to claim 6, characterized in that, Obtaining the actual speed of the planetary rover according to the current pose specifically includes: Constructing the dynamic model of the planetary rover with disturbance terms according to the current pose; Obtaining the target control force and target torque; Obtaining the actual speed according to the target control force, the target torque and the dynamic model of the planetary rover; Wherein, the target control force is the resultant force generated by the wheel hitch traction force of the planetary rover in the planetary rover, and the target torque is the yaw torque generated by the wheel hitch traction force of the planetary rover in the planetary rover.

8. The multi-wheel driving torque coordination control method for a planetary rover according to claim 6, wherein Obtaining the desired longitudinal force and the desired yaw torque based on the sliding mode theory according to the tracking error between the actual speed and the preset speed specifically includes: Obtaining a preset saturation function approaching rate; Obtaining the desired longitudinal force and the desired yaw torque according to the tracking error between the actual speed and the preset speed and the approaching rate of the preset saturation function.

9. A multi-wheel driving torque coordination control device for a planetary rover, characterized in that, Including: An acquisition unit, which is used to acquire the quasi-static mechanical model; The acquisition unit is further used to acquire the current pose and the preset speed of the planetary rover; The acquisition unit is further used to acquire the energy efficiency index of the planetary rover vehicle system, the rocker arm torque balance equation and the wheel torque limit of the planetary rover; A processing unit, which is used to obtain the equivalent concentrated force linear model of a single wheel according to the quasi-static mechanical model; The processing unit is used to construct a dynamic model of the planetary rover with disturbance terms according to the current pose, and obtain the desired longitudinal force and the desired yaw torque based on the sliding mode theory according to the current pose and the preset speed; The processing unit is used to obtain the sum of the unilateral wheel hitch traction forces according to the desired longitudinal force and the desired yaw torque; The processing unit is used to obtain the self-constraint index of the planetary rover according to the energy efficiency index, the rocker arm torque balance equation, the wheel torque limit, the quasi-static mechanical model and the dynamic model of the planetary rover, wherein the self-constraint index is the minimum value of the energy efficiency index; A control unit, which is used to coordinately control the multi-wheel driving torques of the planetary rover according to the equivalent concentrated force linear model of a single wheel, the sum of the unilateral wheel hitch traction forces and the self-constraint index.

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