Wheel-foot robot climbing control method and system based on attitude and torque optimization

Abstract

The invention discloses a wheel-foot robot climbing control method and system based on attitude and torque optimization, and relates to the technical field of robot control. The method comprises the steps that the gravity center of a robot trunk serves as the moment center, and a statics model of a wheel-foot robot on a slope is constructed; quantitatively analyzing the influence of gravity projection, wheelbase and station height of the robot on torque distribution of front and rear wheels, and establishing a torque distribution ratio formula; determining an optimal gravity center projection distance ratio, an optimal axle distance and an optimal station height by taking torque balance as a target; in the actual climbing process of the wheel-foot robot, the projection position of the gravity center of the robot body is obtained in real time, the posture of the wheel-foot robot is adjusted and controlled according to the projection position, the projection position is always located in a safe area of the supporting polygon, and meanwhile the optimal gravity center projection distance ratio, the axle distance and the station height are combined according to the projection position. And torque output of front and rear wheels of the wheel-foot robot is regulated to realize stable climbing. The problem that the wheel-foot robot turns on one side and slips frequently in the process of advancing on the slope can be solved.

Description

Technical Field

[0001] This invention relates to the field of robot hill-climbing control technology, and in particular to a method and system for hill-climbing control of wheeled robots based on posture and torque optimization. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Wheeled robots, with their combined advantages of wheeled and legged locomotion, have broad application prospects in complex terrains (such as steep slopes, ruins, and unstructured terrain in the wild). The motion stability of wheeled robots is a core performance indicator. To achieve stable motion in wheeled robots, traditional control methods often suffer from insufficient terrain adaptability, especially when traversing steep slopes with inclination angles of 45° or higher. For example, using a fixed chassis width or static center of gravity layout cannot dynamically adjust the center of gravity position according to the slope's posture, easily causing the robot to lose balance and tip over backward or forward. Fixed torque distribution strategies concentrate the load on a single wheel, easily leading to wheel slippage when exceeding the slope's friction limit, affecting travel stability. Furthermore, overloading a single wheel not only easily causes slippage but also accelerates mechanical wear on components such as the hub motor and axle, shortening the equipment's lifespan.

[0004] Currently, some existing solutions propose increasing the chassis width to improve stability, but this increases the robot's size and weight, reducing terrain flexibility. Other solutions optimize motor torque output, but they do not consider the relationship between the robot's own structure and torque, and cannot fundamentally solve the problem of uneven load distribution, still resulting in poor climbing stability. Summary of the Invention

[0005] To address the shortcomings of the existing technologies, this invention provides a method and system for controlling the climbing of wheeled robots based on posture and torque optimization. Through dynamic posture adjustment and static modeling optimization, it achieves stable control of the center of gravity and balanced torque distribution, significantly improving its posture stability and ability to pass through steep slopes, reducing mechanical wear, increasing the robot's service life, and solving the problems of rollover and slippage that often occur when wheeled robots travel on slopes.

[0006] In a first aspect, the present invention provides a method for controlling the climbing of a wheeled legged robot based on posture and torque optimization.

[0007] A slope-climbing control method for a wheeled legged robot based on attitude and torque optimization includes: Using the robot's torso center of gravity as the moment center, a static model of the wheeled robot on a slope is constructed. The effects of the robot's center of gravity projection, wheelbase, and standing height on the torque distribution of the front and rear wheels are quantitatively analyzed, and a torque distribution ratio formula is established. Based on the torque distribution ratio formula, with the goal of achieving torque balance, the optimal center of gravity projection distance ratio, wheelbase, and station height are determined. During the actual climbing process of the wheeled robot, the projected position of the robot's torso center of gravity is acquired in real time. The posture of the wheeled robot is adjusted according to the projected position to ensure that the projected position always falls within the safe area of ​​the supporting polygon. At the same time, the output of the torque of the front and rear wheels of the wheeled robot is adjusted according to the projected position in combination with the optimal center of gravity projection distance ratio, wheelbase and standing height to achieve stable climbing.

[0008] In a further technical solution, the center of gravity projection refers to a virtual point on the slope surface where the robot's torso center of gravity is projected vertically; the wheelbase refers to the distance between the robot's front and rear wheels; and the standing height refers to the vertical distance from the robot's torso center of gravity to the slope surface. The center of gravity projection distance ratio k refers to the ratio of the distance a from the front wheel to the center of gravity projection to the wheelbase L, and the ratio of the standing height to the wheelbase is the standing height wheelbase ratio λ. The safe zone refers to the stable area inside the polygon supported by the wheeled robot. The polygon is a convex polygon formed by connecting the contact points of the robot's wheels and the slope surface in sequence.

[0009] Further technical solutions include constructing a static model of the wheeled robot on a 45° slope, including: Using the robot's torso center of gravity as the moment center, static equilibrium equations and moment equilibrium equations are established. The static equilibrium equations include force equilibrium equations along the horizontal direction of the 45° slope and force equilibrium equations perpendicular to the 45° slope, expressed as follows: ; ; Therefore, the torque balance equation is expressed as: ; In the above formula, This represents the tangential force along the slope direction of the front and rear wheels. This represents the force exerted on the front and rear wheels in the direction perpendicular to the slope. This represents the distance from the front wheel to the center of gravity projection. H represents the distance from the rear wheel to the center of gravity projection, H represents the standing height, and G represents the robot's gravity. This represents the component of gravity G along the slope. Let G represent the component of gravity G perpendicular to the slope. Since the slope is 45°, then... .

[0010] Further technical solutions, based on a static model, quantitatively analyze the impact of the robot's center of gravity projection, wheelbase, and standing height on the torque distribution between the front and rear wheels, and establish a torque distribution ratio formula, including: Based on the static model, the normal forces of the front and rear wheels are derived and expressed as: ; ; Based on the normal forces of the front and rear wheels, combined with the wheel radii and friction coefficients, the maximum torque distribution between the front and rear wheels is calculated, and thus the maximum torque distribution ratio between the front and rear wheels is obtained, expressed as: Γ ; Introducing the center of gravity projection distance ratio Station height-to-axis distance ratio The torque distribution ratio formula is: Γ ; In the above formula, H represents the station height, and L represents the wheelbase. .

[0011] A further technical solution, based on the torque distribution ratio formula, aims to achieve torque balance by making the torque distribution ratio approach 1, while reducing the station height-to-wheelbase ratio, and solving for the optimal center of gravity projection distance ratio under a 45° slope environment. Based on the actual configuration constraints of the wheeled robot, a simulation experiment was conducted on the wheeled robot in a 45° slope environment to optimize the center of gravity projection distance ratio and select the wheelbase, standing height and their ratio. In the case of a 45° slope, the optimal values ​​are: k≈0.45, L=1.8m, H=0.5m, λ=H / L≈0.278.

[0012] Secondly, the present invention provides a slope climbing control system for wheeled legged robots based on posture and torque optimization.

[0013] A slope-climbing control system for a wheeled legged robot based on attitude and torque optimization, comprising: The static modeling and torque analysis module is used to construct a static model of the wheeled robot on a slope with the robot's torso center of gravity as the torque center, quantitatively analyze the influence of the robot's center of gravity projection, wheelbase and standing height on the torque distribution of the front and rear wheels, and establish a torque distribution ratio formula. The parameter solving and setting module is used to determine the optimal center of gravity projection distance ratio, wheelbase, and station height based on the torque distribution ratio formula, with the goal of achieving torque balance. The attitude and torque adjustment module is used to obtain the projected position of the robot's torso center of gravity in real time during the actual climbing process of the wheeled robot. The attitude of the wheeled robot is adjusted according to the projected position so that the projected position always falls within the safe area of ​​the supporting polygon. At the same time, the output of the torque of the front and rear wheels of the wheeled robot is adjusted according to the projected position in combination with the optimal center of gravity projection distance ratio, wheelbase and standing height to achieve stable climbing.

[0014] In a further technical solution, the center of gravity projection refers to a virtual point on the slope surface where the robot's torso center of gravity is projected vertically; the wheelbase refers to the distance between the robot's front and rear wheels; and the standing height refers to the vertical distance from the robot's torso center of gravity to the slope surface. The center of gravity projection distance ratio k refers to the ratio of the distance a from the front wheel to the center of gravity projection to the wheelbase L, and the ratio of the standing height to the wheelbase is the standing height wheelbase ratio λ. The safe zone refers to the stable area inside the polygon supported by the wheeled robot. The polygon is a convex polygon formed by connecting the contact points of the robot's wheels and the slope surface in sequence.

[0015] Thirdly, the present invention also provides an electronic device, comprising: a memory for storing executable instructions; and a processor for implementing the above-described method for controlling the climbing of a wheeled robot based on dynamic adjustment of torso posture when executing the executable instructions stored in the memory.

[0016] Fourthly, the present invention also provides a computer-readable storage medium storing executable instructions for causing a processor to execute the executable instructions to implement the above-described method for controlling the climbing of a wheeled robot based on dynamic adjustment of torso posture.

[0017] Fifthly, the present invention also provides a computer program product comprising executable instructions stored in a computer-readable storage medium; wherein, when the processor of the electronic device reads the executable instructions from the computer-readable storage medium and executes the executable instructions, the above-mentioned method for controlling the climbing of a wheeled robot based on dynamic adjustment of torso posture is realized.

[0018] The above one or more technical solutions have the following beneficial effects: 1. To address the common issues of tipping over and slipping during ramp travel in wheeled robots, this invention provides a ramp control method and system for wheeled robots based on posture and torque optimization. By actively and dynamically adjusting the torso posture, the robot's center of gravity is moved along the ramp direction, ensuring that the center of gravity projection remains within the safe area of ​​the supporting polygon and stabilizes in the target area. This effectively eliminates overturning moments and avoids the risk of forward or backward tipping over during ramp travel from a plane to a ramp and during ramp travel, enabling stable travel on a 45° steep ramp. Furthermore, to analyze influencing factors in depth, a static model is established, theoretically revealing the quantitative relationship between the hub motor output torque and the robot's wheelbase and standing height. Based on this model, the optimal distribution scheme of load and torque for the front and rear wheels is further optimized, significantly reducing the load and torque requirements of a single wheel, reducing reliance on wheel-ground friction, improving wheel-ground grip, and preventing slippage and mechanical wear.

[0019] 2. This invention optimizes the center of gravity distribution and torque distribution through posture adjustment and load optimization, balances the load on a single wheel, avoids local overload, effectively reduces the risk of single wheel load and slippage, improves its posture stability on steep slopes and its ability to pass through complex environments, reduces mechanical wear, and increases the robot's service life. Compared with existing methods, it does not require increasing the chassis volume, and improves terrain adaptability through active control strategies, making it suitable for various wheeled robot motion control scenarios in complex terrains with large inclination angles.

[0020] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0022] Figure 1 This is an overall flowchart of the slope climbing control method for a wheeled legged robot based on dynamic adjustment of torso posture in an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the effect of robot torso posture adjustment on the center of gravity projection position in an embodiment of the present invention; wherein, (a) is the running state of the wheeled robot on a horizontal plane; (b) is the running state of the wheeled robot when it enters a slope from a horizontal plane; and (c) is the running state of the wheeled robot on a slope. Figure 3 This is a schematic diagram of the force analysis of the wheeled robot on a 45° slope in an embodiment of the present invention; Figure 4 This is a schematic diagram of the curve of the left rear wheel torque changing with time obtained from simulation in an embodiment of the present invention. Detailed Implementation

[0023] It should be noted that the following detailed descriptions are exemplary and are intended only to describe specific embodiments and to provide further explanation of the invention, and are not intended to limit the scope of exemplary embodiments of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] To address the issues of rollover, slippage, and mechanical wear that wheeled robots often experience when traversing steep slopes of 45° or higher, this invention proposes a slope-climbing control method for wheeled robots based on posture and torque optimization. This method is divided into a design phase and a control phase. In the design phase, a static model of a 45° slope is constructed, and the quantitative relationship between the hub motor torque and the wheelbase L and standing height H is derived. Based on this theoretical correlation, the optimal load distribution ratio k and the optimization direction of the standing height-to-wheelbase ratio λ are pre-optimized and verified through simulation. In the control phase, the robot actively adjusts its torso posture in real time to adjust the center of gravity projection position. a Dynamically maintain within the safe area of ​​the supporting polygon, and then based on the current... a By substituting the values ​​and preset parameters into the correlation formula, the torque distribution ratio Γ of the front and rear wheels is dynamically output and the execution is controlled. This enables the wheeled robot to move stably on a 45° steep slope, reducing the risk of slippage and mechanical wear. It can effectively enhance its adaptability to complex terrain with large inclination angles and is suitable for the motion control of wheeled robots in complex terrain.

[0025] Example 1 This embodiment provides a slope climbing control method for a wheeled legged robot based on attitude and torque optimization, such as... Figure 1 As shown, the specific steps include: Step S1: Using the robot's torso center of gravity as the moment center, construct a static model of the wheeled robot on a slope, quantitatively analyze the influence of the robot's center of gravity projection, wheelbase, and standing height on the torque distribution of the front and rear wheels, and establish a torque distribution ratio formula. Step S2: Based on the torque distribution ratio formula, with the goal of achieving torque balance, determine the optimal center of gravity projection distance ratio, wheelbase, and station height; Step S3: During the actual climbing process of the wheeled robot, the projected position of the robot's torso center of gravity is obtained in real time. The posture of the wheeled robot is adjusted according to the projected position so that the projected position always falls within the safe area of ​​the supporting polygon. At the same time, the output of the front and rear wheel torques of the wheeled robot is adjusted according to the projected position in combination with the optimal center of gravity projection distance ratio, wheelbase and standing height to achieve stable climbing.

[0026] Taking a wheeled robot climbing a 45° slope as an example, the following content will provide a more detailed introduction to the wheeled robot climbing control method based on attitude and torque optimization proposed in this embodiment.

[0027] In the scenario where the wheeled robot climbs a 45° slope, the core control reference is first defined as follows: (1) Definition of the supporting polygon: It is formed by the contact points between the front and rear wheels of the robot and the ground. Due to the characteristics of the wheel foot structure, the contact points are two key support points at the front and rear, thus forming a line segment supporting polygon. The range of this polygon is the "safe boundary" of the center of gravity projection. Once the center of gravity projection exceeds this safe boundary, the robot will face the risk of tipping over (tipping backward or forward).

[0028] (2) Optimization of the target position and torque of the center of gravity projection: Based on the conclusion of static modeling, the center of gravity projection is made to be neither close to the rear wheel contact point (to avoid the back roll torque) nor close to the front wheel contact point (to avoid the front wheel overload and slippage), and finally point to the projection position that makes the load and torque distribution between the front and rear wheels more balanced, so as to ensure the stability of the robot. On this basis, the huge torque pressure and slippage risk faced by the rear wheel during the climbing process are alleviated through the corresponding torque control strategy.

[0029] Therefore, in this embodiment, to ensure the wheeled robot moves stably on a fixed 45° slope, it is first necessary to dynamically adjust the torso posture (actually, torso posture adjustment refers to adjusting the robot's torso pitch angle, i.e., actively adjusting the robot's torso pitch angle) to control the position of its center of gravity (CoM) projection, so that the CoM projection always falls within the safe area of ​​the supporting polygon. This safe area refers to the stable region inside the supporting polygon of the wheeled robot, which is a convex polygon formed by sequentially connecting the contact points of the robot's wheels and the slope surface.

[0030] like Figure 2 As shown, by actively adjusting the posture of the torso, the center of gravity is pulled to move along the slope direction, so that the projected position approaches and stabilizes in the target area, thus ensuring the stability of the wheeled robot climbing the slope. The adjustment principle is as follows: the robot torso and the base (i.e. the wheeled part) are connected by joints, and the pitch angle of the torso can be changed by driving the joints, so that the wheeled robot tilts forward or backward.

[0031] Specifically, the robot, driven by torque in horizontal motion, suddenly changes its terrain angle from 0° to 45° when entering a 45° slope from a horizontal plane. If the robot directly adopts the center-of-gravity posture (center-of-gravity projection centered) from the horizontal plane, the gravitational component of the slope will instantly generate a forward tilting torque. At this point, the position of the support polygon formed by the wheel-foot contact points changes with the slope, and the original safe projection area of ​​the horizontal plane is no longer applicable. If not actively adjusted, the center-of-gravity projection is likely to exceed the front end of the support polygon, leading to front wheel overload or even forward rollover. Therefore, by adapting the support polygon of the transition phase with a backward tilting posture (projection backward), the robot actively adjusts its torso pitch angle to tilt the body backward, allowing the center-of-gravity projection to move backward along the slope direction. This causes the center-of-gravity projection to fall back into the safe area of ​​the support polygon at the moment of transition from the plane to the slope, offsetting the forward tilting torque of the transition phase, preventing the front wheels from slipping due to instantaneous overload, and reserving posture adjustment space for subsequent stable climbing phases, preventing imbalance caused by sudden posture changes.

[0032] The above strategy is actually an active safety strategy, which allows the upper part of the robot's body to tilt backward along the slope, causing the overall center of gravity to shift backward along the slope, thus avoiding overturning due to changes in slope.

[0033] Furthermore, after driving the wheel-legged robot with the original torque and adjusting its posture to safely and stably enter a 45° slope, it proceeds with a stable climbing process. During this process, the robot's body tilts forward along the slope, causing the overall center of gravity to shift forward along the slope direction. This brings the center of gravity projection closer to the front wheel side of the supporting polygon, counteracting the tendency to tip over during climbing. In other words, during the wheel-legged robot's climbing process, tilting the entire body forward causes this posture change to effectively shift the center of gravity forward along the slope direction, thereby achieving: (1) Avoid overturning: Keep the center of gravity projection within a stable range and eliminate the torque that would cause it to overturn.

[0034] (2) Reduce the risk of slippage: Optimize the center of gravity distribution and reduce excessive reliance on wheel friction.

[0035] (3) Enhance grip: Improve wheel-ground contact force distribution and enhance adaptability on uneven slopes.

[0036] During the climbing process, the robot's posture stability on steep slopes is improved by optimizing the center of gravity distribution. At the same time, considering that excessive single-wheel load will aggravate slippage and mechanical wear, it is also necessary to adjust the robot's torque during the climbing process. In this embodiment, a static model is established to reveal the quantitative relationship between the output torque of the hub motor and the robot's wheelbase L and standing height H. Based on this model, the front and rear wheel load distribution scheme is further optimized, which effectively reduces single-wheel load, slippage risk and mechanical wear.

[0037] Specifically, in step S1, a static model of the wheeled robot on a 45° slope is constructed with the robot's torso center of gravity as the moment center. This model is used to quantitatively analyze the impact of posture adjustment and structural parameters (L, H) on stability and drive requirements, and to establish a torque distribution ratio formula.

[0038] like Figure 3 As shown, based on the force analysis of the robot on a 45° slope, a static model is constructed. This model includes: static equilibrium equations and moment equilibrium equations established with the robot's torso center of gravity as the moment center. The static equilibrium equations include force equilibrium equations along the horizontal direction of the slope and force equilibrium equations perpendicular to the slope, expressed as follows: ; ; The torque balance equation is expressed as: ; In the above formula, This represents the tangential force along the slope direction of the front and rear wheels. This represents the force exerted on the front and rear wheels in the direction perpendicular to the slope. This represents the distance from the front wheel to the center of gravity projection. H represents the distance from the rear wheel to the center of gravity projection, H represents the standing height, and G represents the robot's gravity. This represents the component of gravity G along the slope. Let G represent the component of gravity G perpendicular to the slope. Since the slope is 45°, then... .

[0039] Furthermore, based on the static model, the normal forces of the front and rear wheels are derived, expressed as: ; .

[0040] Secondly, based on the normal forces of the front and rear wheels, combined with the wheel radii and friction coefficients, the maximum torque distribution between the front and rear wheels is calculated, thus deriving the maximum torque of the front and rear wheels, which can be expressed as: ; ; In the above formula, Where is the radius of the wheel. is the coefficient of friction.

[0041] The maximum torque distribution ratio between the front and rear wheels is: .

[0042] Finally, the ratio of the projected distance to the center of gravity is introduced. Station height-to-axis distance ratio Then the torque distribution ratio formula can be expressed as: Γ ; In the above formula, H represents the station height, and L represents the wheelbase. .

[0043] Furthermore, in step S2, a torque balance objective is set, and the theoretical value of k is solved. The core objective of optimal k is to achieve balanced torque distribution between the front and rear wheels, i.e., the torque distribution ratio. 1. This avoids slippage caused by single-wheel torque overload, and k is solved using this constraint. In this embodiment, based on the torque distribution ratio formula, with the goal of achieving torque balance, the torque distribution ratio is made to approach 1, i.e. 1. Substituting into the torque distribution ratio formula above, we get: ; Therefore, we can conclude that the theoretical value of k is derived from... Decide, The smaller the ratio (reducing the height-to-wheelbase ratio, i.e., reducing the height H or increasing the wheelbase L), the closer k is to 0.5, which will significantly reduce the maximum torque requirement of the rear wheels. This effectively alleviates the enormous torque pressure and slippage risk faced by the rear wheels during the uphill climb.

[0044] Based on this, this embodiment combines the actual configuration constraints of the wheeled robot to conduct a simulation experiment of the wheeled robot in a 45° slope environment, so as to optimize the center of gravity projection distance ratio and select the wheelbase, standing height and their ratio, and solve for the optimal center of gravity projection distance ratio in a 45° slope environment.

[0045] Specifically, the simulation environment was first set up. A 45° slope environment with a friction coefficient μ=0.6 was constructed in the Webots simulation platform, the URDF model of the wheeled robot was imported, the simulation time step was set to 10ms, and parameters such as maximum torque output and joint limit were configured according to the actual motor performance.

[0046] Secondly, parameter settings and simulation results. Based on the analysis conclusions of the above static model, the projection position is satisfied by adjusting the torso pitch angle. Based on the actual robot configuration constraints, and after multiple simulations and adjustments, the optimal values ​​were finally selected for a 45° slope environment: k=0.45, wheelbase L=1.8m, and standing height H=0.5m (i.e., λ=H / L≈0.278).

[0047] Furthermore, simulation results further validated the effectiveness of this strategy: (1) Attitude adjustment: The robot can dynamically adjust the torso pitch angle according to the strategy requirements.

[0048] (2) Torque Distribution Optimization: Simulation data shows that adjusting L and H changes the torque distribution of the hub motor. The optimized load distribution (based on k and a smaller λ) significantly reduces the fluctuation range of the rear wheel torque, such as... Figure 4 The torque curve of the left rear wheel is shown.

[0049] (3) Improved stability: With the selected parameters of L=1.8m and H=0.5m, the robot can climb to the top of the slope stably, the torque distribution is balanced, and the slippage phenomenon is effectively suppressed.

[0050] Finally, in step S3, the wheeled robot equipped with the above method performs a 45° slope climbing task to verify the reliability and practicality of the method under complex terrain conditions. The specific process is as follows: A 45° slope climbing test was conducted on a self-developed wheeled robot platform. During the actual climbing process, the projected position of the robot's torso center of gravity was acquired in real time. The robot's posture was adjusted based on the projected position to ensure that the projected position always fell within the safe area of ​​the supporting polygon. Simultaneously, the torque output of the front and rear wheels of the wheeled robot was adjusted based on the projected position, the optimal center of gravity projection distance ratio, wheelbase, and standing height to achieve stable climbing. This experiment successfully reproduced the stable climbing behavior in the simulation, and the robot successfully completed the 45° slope climbing task. This fully demonstrates the effectiveness of the posture adjustment and load optimization strategy proposed in this embodiment and its adaptability to complex terrain.

[0051] In summary, the integrated method proposed in this embodiment, which combines dynamic adjustment of torso posture with load distribution optimization based on static modeling, can significantly improve anti-rollover capability by actively adjusting the torso pitch angle to optimize the center of gravity projection position. A static model was established to reveal the quantitative relationship between the torque demand of the hub motor and key structural parameters (wheelbase L, standing height H). Based on this model, the optimal load distribution ratio (k≈0.45) was derived and the influence of λ=H / L was analyzed to guide parameter design. This method can effectively optimize torque distribution, reduce slippage risk, and slow down mechanical wear, ultimately enabling the robot to climb stably and reliably on a 45° steep slope. It significantly enhances the adaptability and motion performance of wheeled robots in complex and rugged terrain, especially on steep slopes.

[0052] Example 2 This embodiment provides a slope-climbing control system for a wheeled robot based on attitude and torque optimization. The system includes: The static modeling and torque analysis module is used to construct a static model of the wheeled robot on a slope with the robot's torso center of gravity as the torque center, quantitatively analyze the influence of the robot's center of gravity projection, wheelbase and standing height on the torque distribution of the front and rear wheels, and establish a torque distribution ratio formula. The parameter solving and setting module is used to determine the optimal center of gravity projection distance ratio, wheelbase, and station height based on the torque distribution ratio formula, with the goal of achieving torque balance. The attitude and torque adjustment module is used to obtain the projected position of the robot's torso center of gravity in real time during the actual climbing process of the wheeled robot. The attitude of the wheeled robot is adjusted according to the projected position so that the projected position always falls within the safe area of ​​the supporting polygon. At the same time, the output of the torque of the front and rear wheels of the wheeled robot is adjusted according to the projected position in combination with the optimal center of gravity projection distance ratio, wheelbase and standing height to achieve stable climbing.

[0053] Furthermore, the aforementioned center of gravity projection refers to the virtual point on the slope surface projected vertically onto the robot's center of gravity; wheelbase refers to the distance between the robot's front and rear wheels; standing height refers to the vertical distance from the robot's center of gravity to the slope surface; the center of gravity projection distance ratio k refers to the ratio of the distance a from the front wheel to the center of gravity projection to the wheelbase L; the ratio of standing height to wheelbase is the standing height-wheelbase ratio λ; the safe zone refers to the stable area inside the polygon supported by the wheeled robot, and the polygon is a convex polygon formed by sequentially connecting the contact points between the robot's wheels and the slope surface.

[0054] Example 3 This embodiment provides an electronic device, including: a memory for storing executable instructions; and a processor for executing the executable instructions stored in the memory to implement the method provided in this embodiment.

[0055] Example 4 This embodiment also provides a computer-readable storage medium storing executable instructions, which, when executed by a processor, will cause the processor to execute the method described above in this embodiment.

[0056] Example 5 This embodiment provides a computer program product including executable instructions, which are computer instructions; the executable instructions are stored in a computer-readable storage medium. When the processor of an electronic device reads the executable instructions from the computer-readable storage medium and executes the executable instructions, the electronic device performs the method described in this embodiment.

[0057] The steps and methods involved in Embodiments 2 to 5 above correspond to those in Embodiment 1. For specific implementation details, please refer to the relevant description section of Embodiment 1. The term "computer-readable storage medium" should be understood as a single medium or multiple media including one or more instruction sets; it should also be understood as including any medium capable of storing, encoding, or carrying an instruction set for execution by a processor and enabling the processor to perform any of the methods in this invention.

[0058] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computer devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computer device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. The present invention is not limited to any particular combination of hardware and software.

[0059] The above description is only a preferred embodiment of the present invention. Although the specific implementation of the present invention has been described in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that, based on the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative effort are still within the scope of protection of the present invention.

Claims

1. A method for controlling a climbing of a wheeled-legged robot based on posture and torque optimization, characterized in that, Comprise: A statics model of the wheel-legged robot on the slope surface is constructed with the robot torso gravity center as the center of gravity, the influence of the robot gravity center projection, the wheelbase and the stance height on the front and rear wheel torque distribution is quantitatively analyzed, and a torque distribution ratio formula is established; Based on the torque distribution ratio formula, the optimal gravity center projection distance ratio, the wheelbase and the stance height are determined with the goal of achieving torque balance; In the actual climbing process of the wheel-legged robot, the projection position of the robot torso gravity center is obtained in real time, the posture of the wheel-legged robot is adjusted according to the projection position, so that the projection position always falls within the safe area of the support polygon, and the output of the front and rear wheel torque of the wheel-legged robot is adjusted according to the projection position in combination with the optimal gravity center projection distance ratio, the wheelbase and the stance height, so as to realize stable climbing.

2. The pose and torque optimization based climbing control method for a wheel-legged robot according to claim 1, wherein, The gravity center projection refers to a virtual point of the robot torso gravity center projected along the vertical direction onto the slope surface; the wheelbase refers to the distance between the front and rear wheels of the robot; and the stance height refers to the vertical distance from the robot torso gravity center to the slope surface. The gravity center projection distance ratio k refers to the ratio of the distance a from the front wheel to the gravity center projection to the wheelbase L, and the ratio of the stance height to the wheelbase is the stance height to wheelbase ratio λ. The safe area refers to a stable area within the support polygon of the wheel-legged robot, and the polygon is a convex polygon formed by sequentially connecting the contact points of the robot legs and the slope surface. 3.The attitude and torque optimization based climbing control method of a wheel-legged robot according to claim 1, wherein, A statics model of the wheel-legged robot on the 45° slope surface is constructed, comprising: A statics balance equation and a moment balance equation are established with the robot torso gravity center as the center of gravity; wherein the statics balance equation includes a force balance equation along the horizontal direction of the 45° slope surface and a force balance equation perpendicular to the direction of the 45° slope surface, and is respectively expressed as: ； ； Then, the moment balance equation is expressed as: ； In the above formulae, represents the tangential force of the front and rear wheels along the slope direction, represents the force of the front and rear wheels perpendicular to the slope direction, represents the distance from the front wheel to the gravity center projection, represents the distance from the rear wheel to the gravity center projection, H represents the standing height, and G represents the robot gravity, represents the component of the gravity G along the slope direction, represents the component of the gravity G perpendicular to the slope direction, and since the slope is 45°, . 4.The attitude and torque optimization based climbing control method of a wheel-legged robot according to claim 3, wherein, Based on the statics model, the influence of the robot gravity center projection, the wheelbase and the stance height on the front and rear wheel torque distribution is quantitatively analyzed, and a torque distribution ratio formula is established, comprising: Based on the statics model, the front and rear wheel normal forces are derived and expressed as: ； ； Based on the front and rear wheel normal forces, the maximum front and rear wheel torque distribution is calculated in combination with the wheel radius and the friction coefficient, and then the maximum front and rear wheel torque distribution ratio is obtained and expressed as: Γ ; Introducing the barycentric projection distance ratio and the station height-axle distance ratio The torque distribution ratio formula is then Γ ; In the above formula, H represents the height of the station, and L represents the wheelbase. .

5. The gait and torque optimization based climbing control method of a wheel-legged robot according to claim 1, wherein, Based on the torque distribution ratio formula, the optimal gravity center projection distance ratio under the 45° slope surface environment is solved with the goal of achieving torque balance by making the torque distribution ratio tend to 1 and reducing the stance height to wheelbase ratio. In combination with the actual configuration constraints of the wheel-legged robot, a simulation experiment of the wheel-legged robot under the 45° slope surface environment is performed to optimize the gravity center projection distance ratio and select the wheelbase, the stance height and their ratio. Wherein, under the 45° slope surface environment, the optimal values are: k≈0.45, L=1.8m, H=0.5m, λ=H / L≈0.

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6. A pose and torque optimization based climbing control system for a wheeled-legged robot, comprising: Comprise: A statics modeling and torque analysis module is used to construct a statics model of the wheel-legged robot on the slope surface with the robot torso gravity center as the center of gravity, quantitatively analyze the influence of the robot gravity center projection, the wheelbase and the stance height on the front and rear wheel torque distribution, and establish a torque distribution ratio formula; A parameter solving and setting module is used to determine the optimal gravity center projection distance ratio, the wheelbase and the stance height based on the torque distribution ratio formula with the goal of achieving torque balance; The posture and torque adjustment module is used for acquiring the projection position of the robot trunk gravity center in real time during the actual climbing process of the wheel-foot robot, adjusting the posture of the wheel-foot robot according to the projection position, making the projection position always fall within the safe area of the support polygon, and adjusting the output of the front and rear wheel torque of the wheel-foot robot according to the projection position, the optimal gravity center projection distance ratio, the wheelbase and the standing height, so as to realize stable climbing.

7. The pose and torque optimization based climbing control system of a wheel-legged robot according to claim 6, wherein, The gravity center projection refers to a virtual point of the robot trunk gravity center projected along the vertical direction to the slope surface; the wheelbase refers to the distance between the front and rear wheels of the robot; and the standing height refers to the vertical distance from the robot trunk gravity center to the slope surface. The gravity center projection distance ratio k refers to the ratio of the distance a from the front wheel to the gravity center projection to the wheelbase L; and the ratio of the standing height to the wheelbase is the standing height wheelbase ratio λ. The safe area refers to a stable area inside the support polygon of the wheel-foot robot, and the polygon is a convex polygon formed by sequentially connecting the contact points of the robot wheel feet and the slope surface.

8. An electronic device, comprising: The computer program product comprises executable instructions stored in a computer readable storage medium. When the processor of the electronic device reads the executable instructions from the computer readable storage medium and executes the executable instructions, the posture and torque optimization based wheel-foot robot climbing control method in any one of claims 1-5 is realized. The computer program product comprises executable instructions stored in a computer readable storage medium.

9. A computer-readable storage medium, characterized in that, When the processor of the electronic device reads the executable instructions from the computer readable storage medium and executes the executable instructions, the posture and torque optimization based wheel-foot robot climbing control method in any one of claims 1-5 is realized.

10. A computer program product, characterised in that, The computer program product comprises executable instructions stored in a computer readable storage medium. When the processor of the electronic device reads the executable instructions from the computer readable storage medium and executes the executable instructions, the posture and torque optimization based wheel-foot robot climbing control method in any one of claims 1-5 is realized.

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