Spoke variable structure driving wheel for amphibious vehicle and control method

Abstract

The invention discloses a spoke variable structure driving wheel for an amphibious vehicle and a control method. The driving wheel comprises a wheel, a power source, paddles, an angle adjusting mechanism, an angle adjusting driving unit and a vehicle-mounted controller. The vehicle-mounted controller intelligently identifies whether the vehicle is in a land mode or a water mode by fusing multi-source sensor information such as water depth, vehicle speed, posture and steering, and controls the vehicle to advance according to a preset control strategy. In the land driving mode, optimization of driving resistance and stability is taken as a target; and in the underwater floating mode, the adjusting mechanism is triggered, all the blades are driven to rotate to the target angle obtained through calculation according to the control strategy and locked, and the spiral curved surfaces of the blades work as propeller blades. The vehicle-mounted controller can also dynamically and finely adjust the angle of the paddle according to the real-time navigation parameters so as to optimize the underwater propulsion efficiency and the steering maneuverability. Through intelligent mode switching and self-adaptive control, the driving wheel has the functions of efficient land driving and flexible water propelling.

Description

Technical Field

[0001] This disclosure relates to the field of amphibious vehicle technology, and more specifically, to an adjustable-angle drive wheel for amphibious vehicles that integrates an environmental perception and intelligent decision-making control system. Background Technology

[0002] Traditional propulsion systems for amphibious vehicles primarily rely on external attachments. The mainstream approach involves adding independent propellers or water jet propulsion pumps to the rear or sides of the vehicle. While these solutions provide effective thrust, they generally suffer from the following drawbacks: the addition of an independent drive system and transmission mechanism leads to a more complex vehicle structure, increased weight, and larger footprint; furthermore, the complex control logic for switching between land and water modes places higher demands on vehicle integration and control.

[0003] To eliminate the need for external propulsion, a highly integrated approach has emerged: integrating the propulsion function directly into the wheel. For example, some solutions involve fixing water-pushing blades to the spokes of existing wheels. However, while such integration simplifies the system, it typically has significant limitations: fixed blades or auxiliary wheels introduce additional air resistance and weight when traveling on land, potentially affecting safety; furthermore, they lack the ability to actively adjust their state according to the water and land environment, failing to achieve optimal performance between the two modes.

[0004] In conclusion, neither external propulsion systems nor the initial spoke-integrated design have ideally resolved the contradiction between "high integration," "mode adaptation," and "optimal performance across all operating conditions." Specifically, there is still a lack of a truly integrated solution that enables wheels to actively and intelligently change their shape in both land and water environments, maintaining low drag and high efficiency on land and flexibly transforming into a high-efficiency propulsion mechanism when navigating water. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an intelligent, adaptive integrated amphibious drive wheel solution. Its core lies in the deep integration of mechanical actuators with an advanced multimodal intelligent control system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A spoke-variable structure drive wheel for amphibious vehicles and a control method thereof, characterized in that it includes: The mechanical actuator includes: a wheel consisting of a hub, spokes, rim, and tire; a power source that provides driving force to the wheel; a blade mounted on the spokes; an angle adjustment mechanism for synchronously adjusting the working angle of the blade; and an angle adjustment drive unit that provides driving force to the angle adjustment mechanism. The sensing unit includes a water depth sensor, a vehicle speed sensor, an accelerator pedal sensor, a steering angle sensor, a yaw rate sensor, and a blade angle sensor. These sensors are configured to collect water depth information and vehicle speed information in real time, power demand information, steering angle information, and yaw rate information in real time, and blade deflection angle information in real time, respectively. The control unit is communicatively connected to the mechanical actuator and the sensing unit. The control unit internally stores a mode switching program for identifying the driving environment conditions of the vehicle, a driving control program for controlling the drive wheels to drive the vehicle and actively adjusting the mechanical actuator, and a control method for a wheel spoke variable structure for amphibious vehicles.

[0007] A wheel specifically includes a hub, spokes, rim, and tire. The inner ring of the hub is mounted to the end of the steering knuckle via a hub bearing. The outer ring, spokes, and rim are integrally formed. The spokes are evenly distributed circumferentially between the hub and rim, and are cylindrical in shape for mounting the blades. The inner ring of the hub has splined grooves that connect to the half-shaft drive for transmitting drive torque.

[0008] The power source that provides driving force to the wheels adopts a wheel-side drive configuration and is fixedly installed on the side of the suspension system or frame. The half-shaft passes through the inner hole of the steering knuckle, and its outer end is connected to the wheel hub via a spline. The power source can output torque, which drives the wheel hub to rotate through the half-shaft, enabling the vehicle to travel on land or float in water.

[0009] The propeller blades are of a clip-on helical blade structure. Each blade consists of blade one and blade two, which are fixedly connected by four sets of bolts and nuts. Blade one has a ball joint near the wheel center that mates with a connecting rod. After installation, the blades can rotate around the axis of the wheel spokes. The blades adopt a variable cross-section helical curved surface configuration, with an airfoil cross-section that is thick in the middle and thin at both ends, forming an overall helical shape. The airfoil cross-section changes continuously along the radial direction of the wheel, forming the working surface of the blade. When the vehicle floats in water, the interaction between the working surface and the water generates a force along the longitudinal direction of the vehicle.

[0010] An angle adjustment mechanism includes a push-pull ring connected to an angle adjustment drive unit via a ball joint, an outer spherical bearing with an interference fit to a half-shaft, a flange rotatably supported by the outer spherical bearing and the half-shaft, a disc-shaped component fixedly connected to the flange, multiple connecting rods for connecting the blade and the disc-shaped component, a bearing assembly for rotatably supporting the push-pull ring, a pressure plate for pressing the bearing assembly, and a retaining ring for axially positioning the bearing assembly; the push-pull ring is rotatably supported by the bearing assembly and the flange, such that the... The oscillation of the push-pull ring can be transmitted to the flange, while the push-pull ring does not rotate with the flange. The wheel end of each link is connected to one of the blades via a ball joint, and the vehicle body end is connected to the disc-shaped component via a ball joint. When the angle adjustment drive unit drives the push-pull ring to oscillate, the push-pull ring deflects at a certain angle along the outer surface of the outer spherical bearing via the flange and the disc-shaped component of the bearing assembly. This deflection, in turn, drives all the blades to rotate synchronously around their respective spoke axes at unequal angles, achieving dynamic adjustment of the blade angle according to the wheel rotation angle. When the wheel rotates, the blade with the larger deflection angle generates a greater force along the vehicle's longitudinal direction than the blade with the smaller deflection angle. The longitudinal forces generated by each blade are superimposed to form a resultant force, which is the thrust required for the vehicle to navigate in water.

[0011] The angle adjustment drive unit includes a trapezoidal lead screw and nut mechanism, a drive motor for driving the trapezoidal lead screw, and a housing. The body end of the trapezoidal lead screw is connected to the drive motor via a coupling, and the wheel end is rotatably supported by the housing via a bearing. The trapezoidal lead screw and nut mechanism has a self-locking function: when the thread helix angle is less than or equal to the equivalent friction angle, the trapezoidal lead screw will not rotate in the opposite direction or slip under axial load. The equivalent friction angle is determined by the friction coefficient of the thread pair and the thread profile half-angle; when the tangential force generated by the axial force is insufficient to overcome the frictional resistance between the thread pairs, the trapezoidal lead screw and nut mechanism achieves self-locking. The drive motor is fixedly mounted on the steering knuckle, and its output shaft is fixedly connected to the body end of the lead screw via a coupling. The housing is fixedly mounted on the steering knuckle, covering the trapezoidal lead screw and nut mechanism and the drive motor, to protect them from external environmental corrosion and mechanical damage. When the angle adjustment drive unit is working, the drive motor drives the trapezoidal lead screw to rotate. The rotational motion of the lead screw is converted into the linear motion of the push-pull ring via the lead screw and nut pair, thereby driving the angle adjustment mechanism. After adjustment, the self-locking characteristic of the trapezoidal lead screw maintains the blade angle unchanged, eliminating the need for continuous power supply, thus reducing energy consumption and improving system reliability. This angle adjustment drive unit has a compact structure and reliable self-locking mechanism. Working in conjunction with the angle adjustment mechanism, it enables the amphibious vehicle to switch modes and maintain its angle.

[0012] The mode switching procedure is pre-programmed to accurately identify whether the vehicle is currently in "Land Driving Mode" or "Water Floating Mode." "Land Driving Mode" refers to the vehicle's operating state, where it determines based on sensor information that it is in a land or shallow water environment and focuses on land maneuverability as the core control objective. In this mode, the system controls the angle adjustment mechanism to adjust the propeller blades to the optimized target angle for the Land Driving Mode and locks the blade angle, while simultaneously controlling the power source providing driving force to the wheels to provide conventional ground traction. "Water Floating Mode" refers to the vehicle's operating state, where it determines based on sensor information that it has entered water and focuses on water navigation as the core control objective. In this mode, the system controls the angle adjustment mechanism to simultaneously deploy all propeller blades to a specific water propulsion angle and locks them, allowing the blades to function as propeller blades, providing the vehicle with primary thrust and steering control torque. Therefore, in Land Driving Mode, all propeller blades are adjusted to a fixed angle. In underwater floating mode, the propeller angle is dynamically adjusted according to the phase of the wheel rotation with the goal of generating maximum thrust: that is, when the propeller blades rotate to their highest point, their angle is adjusted to... When the blades rotate to their lowest point, their angle is adjusted to... The above angle parameters The absolute angle of the tangent line at the center point of the intersection of the end face of blade one near the hub and the contact surface of blade two with respect to the end face of the hub. Computational fluid dynamics (CFD) simulation analysis determined that, for floating conditions in water, with maximizing propulsion efficiency as the optimization objective, the relationship between the longitudinal thrust generated by wheel rotation and the blade angle was obtained through simulation, thus yielding the angle with optimal propulsion efficiency. Simulation results show that when the blade angle is within the specified range, the performance requirements of low-drag travel on land and high-efficiency propulsion in water can be simultaneously met.

[0013] The driving control program is configured to execute the following control strategies based on the mode judgment result output by the mode switching program: In land driving mode, the drive control command controls the wheel rotation direction to adapt to the vehicle's driving direction, and the blade target angle control command controls the blade rotation angle of the left and right wheels to be consistent; in water-floating mode, when the vehicle is traveling straight, the drive control command is speed control, and the blade target angle control command controls the blades of the left and right wheels to deflect in opposite directions and at equal angles; in water-floating mode, when the vehicle turns or makes a U-turn, the drive control command is wheel differential compensation control, or controls the rotation direction of the left and right wheels to be opposite, and the blade target angle control command is blade differential angle compensation control; thereby generating thrust of unequal magnitude on both sides to form the steering torque required for different turning radii.

[0014] The travel control program is also configured to execute the following controls: speed control: based on the difference between the vehicle's actual speed and the target speed, control the wheel rotation direction to adapt to the vehicle's travel direction, and dynamically adjust the output torque of the drive wheels to achieve closed-loop speed control; wheel differential compensation control: based on the vehicle's actual yaw rate and the target yaw rate obtained from the steering command in the operating attitude information, generate differential compensation commands for the left and right drive wheels; according to the differential compensation commands, control the left and right drive wheels of the vehicle to rotate in the same direction at different speeds to assist the vehicle in turning on the water surface; blade differential angle compensation control: based on the vehicle's actual yaw rate and the target yaw rate obtained from the steering command in the operating attitude information, generate differential angle compensation commands for the left and right angle adjustment drive units of the vehicle; according to the differential angle compensation commands, control the deflection angles of the blades of the left and right drive wheels of the vehicle to be opposite, and the target deflection angles of the blades of the left and right drive wheels of the vehicle to be unequal, to assist the vehicle in turning on the water surface.

[0015] Control methods, specifically including: When the vehicle has a distributed drive architecture, meaning each wheel is driven by an independent power source, the specific execution steps of the control method are as follows: The system continuously reads vehicle operating environment information and vehicle attitude information from the sensing unit. The environmental information includes water depth and vehicle speed, while the vehicle attitude information includes power demand, steering angle, and yaw rate. The system then transmits the vehicle operating environment information to the mode switching program and the vehicle attitude information to the driving control program. The mode switching program, based on the vehicle operating environment information read by the sensing unit, determines the appropriate driving mode for the vehicle in real time and transmits the result to the driving control program. Finally, the driving control program, based on the mode determination result from the mode switching program and the vehicle attitude information read by the sensing unit, identifies the driver's intention in real time, retrieves the corresponding control strategy, and generates drive control commands and blade target angle control commands. The control strategy includes: In land driving mode, the drive control command controls the wheel rotation direction to adapt to the vehicle's driving direction, and the blade target angle control command controls the blade rotation angle of the left and right wheels to be consistent. In the floating mode, when the vehicle is traveling straight, the drive control command is for speed control, and the blade target angle control command is to control the blades of the left and right wheels to deflect in opposite directions and at equal angles. In the floating mode, when the vehicle turns or turns around, the wheel differential compensation control is mainly invoked to generate speed compensation commands for the left and right wheels, so that the left and right wheels rotate in the same direction at different speeds or rotate in opposite directions at the same speed, so that the two sides generate thrust of different magnitudes to form the required steering torque. After the command is executed, the sensor unit is retrieved to read the deflection angle information of the propeller blades, and the information is continuously fed back to the mode switching program and the travel control program to form a closed-loop control.

[0016] When the vehicle has a centralized single-motor drive architecture, that is, the whole vehicle is driven by a single power source, the left and right wheels are mechanically connected through a differential. Since the speed of the left and right wheels cannot be controlled independently, the control strategy when turning or turning in the floating mode should be adjusted to: mainly call the blade difference angle compensation control strategy to generate blade angle difference commands for the left and right wheels, so that the deflection angles of the blades on both sides are different, thereby generating thrust of different magnitudes to form the required steering torque; Safety monitoring and fault tolerance strategies: The control method also has the ability to monitor feedback signals such as the current of the drive motor and the blade angle in the angle adjustment drive unit in real time. Once an abnormality such as stall or lock failure is detected, a safety strategy is immediately triggered, such as stopping the action, issuing an alarm, or attempting to return to a safe angle, where the safe angle is the target angle of the blade when the vehicle is in land driving mode.

[0017] The beneficial effects of this invention are: 1. This invention addresses the core engineering challenge of effectively driving distributed-drive electric vehicles in amphibious environments by proposing a complete drive system solution. Traditional vehicles rely on external propellers or water jets for water propulsion, resulting in bulky structures and complex systems; while relying solely on wheel propulsion suffers from low efficiency and insufficient thrust. This invention integrates wheels and propellers into the drive wheels of amphibious vehicles, enabling the same set of wheels to actively change shape according to the driving environment, fundamentally solving the problem of functional reuse in amphibious drive systems.

[0018] 2. Compared with existing technologies, this invention has significant uniqueness. Existing solutions often only allow for simple switching between land and water modes, failing to address the different requirements of the blade tilt angle for each condition—land travel requires the blades to be retracted to reduce rolling resistance, while water travel requires the blades to be extended to a specific angle to generate effective thrust. The drive wheel system proposed in this invention, through precise control of the blade tilt angle, can simultaneously meet the conflicting requirements of blade attitude for both land and water conditions, achieving a perfect unity of "low-resistance rolling on land" and "efficient propulsion in water."

[0019] 3. To achieve the aforementioned variable structure function, this invention designs an actuation scheme that combines an independent angle adjustment drive unit with a mechanical actuator. This angle adjustment drive unit consists of a trapezoidal lead screw and nut mechanism, a drive motor driving the trapezoidal lead screw, and a housing. It can precisely control all blades to rotate synchronously to the target angle while the wheel is rotating. Simultaneously, the design of the outer spherical bearing and bearing assembly solves the technical challenge of "stationary components driving rotating components," enabling the fixedly installed drive unit to reliably control the angle of the rotating blades.

[0020] 4. Through the above technical solutions, this invention achieves multiple synergistic effects: the helical surface formed after the blades unfold, combined with precise control of the wheel rotation direction and angle, can generate stable and efficient thrust in water; based on an environmental recognition algorithm using multi-sensor information fusion, the system can automatically identify the water and land environment and complete mode switching; the trapezoidal screw and nut mechanism in the angle adjustment drive unit has a self-locking function, ensuring that the blade angle is stable and reliable in the non-adjustment state. Overall, this invention, through the technical path of "variable structure mechanism + independent actuation + intelligent control," significantly improves the adaptability and reliability of amphibious vehicles in complex environments. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a logic flowchart of the control method in the amphibious vehicle spoke-variable structure drive wheel and control method described in this invention.

[0022] Figure 2 This is a schematic diagram of the structure of the spoke-variable drive wheel for an amphibious vehicle according to the present invention in land driving mode.

[0023] Figure 3 This is a curve showing the change of blade angles with wheel rotation angle in the land driving mode of a amphibious vehicle with a variable spoke structure, as described in this invention.

[0024] Figure 4 This is a schematic diagram of the structure of the spoke-variable drive wheel for an amphibious vehicle described in this invention, in a floating mode in water.

[0025] Figure 5 This invention describes the trend of the blade angles changing with the wheel rotation angle in the floating mode of an amphibious vehicle with a variable spoke structure drive wheel.

[0026] Figure 6 This is a schematic diagram of the overall structure of a spoke-variable drive wheel for an amphibious vehicle according to the present invention.

[0027] Figure 7 This is a three-dimensional exploded view of the drive wheel section of a spoke-variable structure for an amphibious vehicle according to the present invention.

[0028] Figure 8 This is a cross-sectional view of a spoke-variable drive wheel for an amphibious vehicle according to the present invention.

[0029] Figure 9This is a logic flowchart of the mode switching procedure in the control method for a spoke-variable structure drive wheel and control method for an amphibious vehicle described in the control unit of the present invention.

[0030] Figure 10 This is a logic flowchart of the travel control program in the amphibious vehicle spoke-variable structure drive wheel and control method described in the control unit of the present invention.

[0031] Figure 11 This is a block diagram illustrating the closed-loop speed control principle in the underwater floating mode of the amphibious vehicle drive wheel and control method described in this invention.

[0032] Figure 12 This is a schematic diagram of the differential wheel compensation control in the spoke-variable structure drive wheel and control method for an amphibious vehicle described in this invention.

[0033] Figure label: 10 wheels; Blade 20, Blade 1 21, Blade 2 22; Angle adjustment mechanism 30, connecting rod 31, disc-shaped part 32, outer spherical bearing 33, flange 34, bearing assembly 35, push-pull ring 36, pressure plate 37, retaining ring 38; Angle adjustment drive unit 40, nut 41, trapezoidal lead screw 42, drive motor 43, housing 44; Half shaft 50; Brake 60, brake disc 61, brake caliper 62, brake caliper bracket 63; Steering knuckle 70; Wheel hub bearing 80. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the present invention clearer, the implementation of the mechanical execution unit and core control logic and method involved in the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0035] Mechanical Actuation Unit: The mechanical actuation unit of this system provides the physical basis for realizing amphibious drive. Its core includes variable structure blade 20, angle adjustment mechanism 30 and angle adjustment drive unit 40.

[0036] like Figure 7 , 8As shown, the propeller 20 includes a first propeller 21 and a second propeller 22. The first propeller 21 and the second propeller 22 are connected by four sets of bolts and nuts. To optimize wind resistance during land travel and thrust generated by the propellers during underwater navigation, the four sets of bolts and nuts are placed in countersunk holes in the first propeller 21 and the second propeller 22. A ball joint that mates with the connecting rod 31 is arranged at the end of the first propeller 21 near the wheel center. After installation, each propeller blade can rotate around the axis of the spokes on the wheel 10.

[0037] like Figure 2 , Figure 3 As shown, in land driving mode, all propeller blades 20 are in... , Figure 2 This shows the state of the blade 20; Figure 3 The curve showing the change of the blade angle 20 as a function of the wheel rotation angle in the land driving mode is shown.

[0038] like Figure 4 , Figure 5 As shown, in the underwater floating mode, the propeller target angle control command is used to dynamically adjust the propeller angle according to the rotation phase of the wheel: that is, when the propeller rotates to the highest point, its angle is adjusted to 0; when the propeller rotates to the lowest point, its angle is adjusted to... . Figure 4 This shows the state of propeller blade 20 in underwater floating mode. Figure 5 The diagram illustrates the trend of blade 20 angle variation with wheel rotation angle. In underwater floating mode, angle adjustment drive unit 40 drives trapezoidal screw 42 to rotate. Trapezoidal screw 42 drives nut 41 to move axially along the axis of trapezoidal screw. Nut 41 drives push-pull ring 36 to swing. Through bearing assembly 35, flange 34 and disc 32 rotate along the outer surface of outer spherical bearing 33. This rotation, in turn, drives each blade 20 to rotate around its respective spoke axis via connecting rod 31. The blade angle changes with the wheel rotation angle. When steering is required, thrust difference can be generated through differential speed compensation control of the left and right wheels or differential blade angle compensation control to achieve flexible steering.

[0039] like Figure 7 , 8As shown, the angle adjustment mechanism 30 includes a connecting rod 31, a disc-shaped component 32, an outer spherical bearing 33, a flange 34, a bearing assembly 35, a push-pull ring 36, a pressure plate 37, and a retaining ring 38. The connecting rod 31 has spherical grooves at both ends. The ball heads of the impeller blade 21 at the wheel end are connected via ball hinges, and the spherical groove at the vehicle body end is connected to the disc-shaped component 32 via ball hinges. The disc-shaped component 32 is fixedly connected to the flange 34 with screws, and the flange 34 is rotatably supported on the wheel 10 via the outer spherical bearing 33. The push-pull ring 36 is rotatably supported on the flange 34 via the bearing assembly 35, and the outer ring of the push-pull ring 36 has ball heads that mate with the nut 41. The pressure plate 37 and the retaining ring 38 are installed on one side of the bearing assembly 35 to restrict the axial movement of the bearing assembly 35.

[0040] like Figure 7 , 8 As shown, the angle adjustment drive unit 40 includes a nut 41, a trapezoidal lead screw 42, a drive motor 43, and a housing 44. The nut 41 has a spherical groove that mates with a ball head on the push-pull ring 36. The body end of the trapezoidal lead screw 42 is connected to the drive motor 43 via a coupling, and the wheel end is rotatably supported by a bearing on the housing 44. Both the drive motor 43 and the housing 44 are fixed to the steering knuckle 70 with screws.

[0041] The core function of the mechanical actuator is to achieve active adjustment and reliable locking of the blade angle. Its working principle is as follows: After the drive motor 43 in the angle adjustment drive unit 40 is powered on, it drives the trapezoidal lead screw 42 to rotate. The nut 41 converts the rotational motion of the lead screw into its own linear motion, and drives the push-pull ring 36, which is ball-jointed with it, to swing along the outer surface of the outer spherical bearing 33. The push-pull ring 36 transmits the thrust to the flange 34 through the bearing assembly 35. The flange 34 is rotated and supported on the wheel 10 by the outer spherical bearing 33, which drives the disc-shaped part 32, which is fixed to the flange 34, to rotate along the outer surface of the outer spherical bearing 33, causing the disc-shaped part 32 to tilt. The disc-shaped component 32 is connected to each blade 21 via multiple connecting rods 31. Since blade 21 and blade 22 are fixed to the spokes of the wheel 10 by bolts and nuts, and can rotate around the spoke axis after assembly, the rotational motion of the disc-shaped component 32 along the outer surface of the outer spherical bearing 33, via the connecting rods 31, can cause all blades to simultaneously deflect at unequal angles around their respective spoke axes. When the blades reach the target angle, the trapezoidal lead screw 42 achieves self-locking by utilizing its thread helix angle being less than the equivalent friction angle. The positions of the nut 41 and the push-pull ring 36 are maintained, locking the blades at the current angle without continuous power supply. Thus, the mechanical actuator completes the power transmission from motor rotation to blade deflection and achieves self-locking of the adjusted angle, meeting the requirements for switching between land and water blade configurations.

[0042] Control Logic: The focus of this embodiment is to illustrate the integration of the aforementioned mechanical actuator and intelligent control system. The power source and angle adjustment drive unit serve as the direct execution endpoints of the control commands; their actions are precisely calculated by the control unit based on sensor information and then issued. The specific implementation of this intelligent control logic will be described in detail below.

[0043] Core control logic flow: such as Figure 9 As shown, the control unit continuously executes the following cycle: Step S101: Data Acquisition and Fusion. The control unit acquires data from the sensing unit in real time via the CAN bus: the water depth value from the depth sensor. Vehicle speed value from vehicle speed sensor The accelerator pedal opening value from the accelerator pedal sensor, the yaw rate from the yaw rate sensor, the angle from the steering angle sensor, and the blade angle value from the blade angle sensor. .

[0044] Step S102: Intelligent identification of environmental mode. The control unit's mode switching program executes the following judgment logic ( Figure 10 ): Conditions for entering underwater mode: If And duration ,at the same time If the vehicle is detected as having entered the water, it will be determined that it has entered the water and will switch to "floating mode". The threshold for water depth is the water depth required for entry. Water entry velocity threshold, This is the duration threshold.

[0045] Conditions for returning to land mode: If the current mode is underwater, and If the vehicle is found to be ashore, the system determines it has reached the shore and switches back to "land driving mode." The use of hysteresis comparison and delayed judgment effectively prevents mode oscillations caused by brief wading. This is the threshold for the outlet water depth.

[0046] Step S103: Target Angle Decision. Based on the current mode, query the preset mapping table or perform calculations to determine the target angle of the propeller deflection for both land driving mode and water-floating mode: Land driving mode: target angle .

[0047] Floating mode in water: Target angle .

[0048] Based on this, if the mode switching program determines that it is in underwater floating mode, it will perform underwater optimization and dynamic compensation.

[0049] Step S104: Dynamic optimization compensation calculation. This step encompasses two sub-logic: Speed ​​control ( Figure 11 ): Set target speed The actual speed obtained through fusion calculation The comparison yields the error e. This error is input to the PID controller, and its output is the blade angle compensation amount. and power source torque compensation The power source that provides power to the wheels and the angle adjustment drive unit are then adjusted according to the compensation amount.

[0050] Differential compensation control ( Figure 12 Differential compensation control includes wheel differential compensation control and blade angle differential compensation control. When a driver's steering intention is detected (SteerAngle is not zero), if the vehicle has a distributed drive architecture, meaning each wheel is driven by an independent power source, the wheel differential compensation control strategy is invoked to generate speed compensation commands for the left and right wheels. This causes the left and right wheels to rotate in the same direction at different speeds or in opposite directions at the same speed, generating unequal thrust on both sides to form the required steering torque. If the vehicle has a centralized single-motor drive architecture, meaning the entire vehicle is driven by a single power source, since the speeds of the left and right wheels cannot be controlled independently, the blade angle differential compensation control strategy is invoked to generate blade angle differential compensation commands for the left and right wheels. This causes the deflection angles of the blades on both sides to be unequal, thereby generating unequal thrust to form the required steering torque.

[0051] Step S105: Command Issuance and Execution Monitoring. The control unit converts the target rotational speeds of the left and right wheels and the target angles of the left and right wheel blades into control signals for the power source and drive motor 43 that provide power to the wheels, respectively. Simultaneously, it monitors the feedback current of the drive motor 43 and the actual blade angle. If an abnormal increase in feedback current occurs (indicator stalls) or If the error exceeds the tolerance and persists, it is judged as a fault, and the process proceeds to step S106.

[0052] Step S106: Fault Handling and Safety Strategy. Immediately stop the adjustment command, issue an audible and visual alarm, and attempt to control the propeller blades to return to a safe angle, which is the target angle of the propeller blades in land driving mode. At the same time, store and upload the fault code.

[0053] like Figure 1 As shown, the control strategies for propeller angle and wheels in the three operating conditions of the floating mode (straight-line travel, turning, U-turn, and special maneuvering) and the land travel mode are as follows: (I) Straight-line travel condition When traveling straight on water, the control unit aims to maintain a stable course and constant speed.

[0054] Blade angle control: The blades of the left and right wheels deflect in opposite directions and at equal angles, and both angles are adjusted to the same base target angle. This ensures that the left and right wheels generate a combined force in the forward direction.

[0055] Wheel speed control: The wheel speeds of the left and right wheels are controlled by the power source to rotate at the same speed. When it is necessary to adjust the speed, such as... Figure 11 As shown, the control unit compares the actual speed. target speed The PID controller calculates the adjustment amount and dynamically adjusts the blade angle or the output torque of the power source to achieve closed-loop speed control.

[0056] Wheel rotation direction: The left and right wheels rotate in the same direction, both rotating in the same direction as the direction of travel to generate thrust.

[0057] (II) Steering Condition When turning on water, the control unit aims to generate a steering torque to change the course.

[0058] When the vehicle has a distributed drive architecture, meaning each wheel is driven by an independent power source, wheel differential compensation control is used: the control unit calculates the speed differential compensation amount based on the steering command intensity. For a left turn command, the speed of the left wheel is adjusted to... (Thrust decreases), the speed of the right wheel is adjusted to... (Increased thrust) creates a difference in thrust between the left and right sides, generating a steering torque.

[0059] When the vehicle has a centralized single-motor drive architecture, meaning the entire vehicle is driven by a single power source, blade differential angle compensation control is used: the control unit calculates the angle differential compensation amount based on the steering command intensity. Based on the existing left and right wheel blades with opposite deflection directions, for a left turn command, the angle of the left wheel blade is adjusted to... The right wheel blade angle was adjusted to This creates a difference in thrust between the left and right sides, generating a steering torque.

[0060] Wheel rotation direction: During normal forward steering, both left and right wheels rotate in the forward direction (clockwise). The angle difference and speed difference work together to generate steering torque.

[0061] (III) Turning around and special maneuvering conditions When performing a U-turn or special maneuver on water, the control unit adopts a more flexible control strategy.

[0062] Small radius U-turn: When a smaller turning radius is required, it can be further increased. and The value is used to maximize the thrust difference between the inner and outer wheels.

[0063] U-turn: When a near-stationary U-turn is required, the control unit can control the left and right wheels to rotate in opposite directions. For example, the left wheel rotates clockwise (generating forward thrust), and the right wheel rotates counterclockwise (generating backward thrust), forming a couple that causes the vehicle to rotate around its center. Under this condition, the angle of the left and right blades remains constant. However, since the rotation direction is opposite, the thrust direction is also opposite, thus achieving efficient turning in place.

[0064] Lateral and oblique movement: By finely adjusting the angle and speed difference between the left and right wheels, complex maneuvers such as lateral and oblique movement on the water surface can also be achieved.

[0065] (iv) Land-based mode operating conditions Blade angle control: The blades of both the left and right wheels are adjusted to... .

[0066] Wheel speed control: The rotational speed of the left and right wheels is controlled by conventional differential control based on the driver's throttle and steering commands. During steering, the outer wheel rotates faster than the inner wheel, achieving normal Ackermann steering geometry.

[0067] Through the above-described refined operating condition control strategy, this invention achieves optimal performance for amphibious vehicles under different modes and operating conditions, realizing the transformation of a single drive wheel from a "passive actuator" to an "intelligent environmental adaptation unit." The control algorithm can be burned into the memory of the control unit in the form of a software program, constituting a computer-readable storage medium storing a computer program. When the program is executed by the processor, the above-described method is implemented.

[0068] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A spoke-variable structure drive wheel for amphibious vehicles and a control method thereof, characterized in that, The drive wheel includes: The mechanical actuator includes: a wheel consisting of a hub, spokes, rim, and tire; a power source that provides driving force to the wheel; a blade mounted on the spokes; an angle adjustment mechanism for synchronously adjusting the working angle of the blade; and an angle adjustment drive unit that provides driving force to the angle adjustment mechanism. The sensing unit includes a water depth sensor, a vehicle speed sensor, an accelerator pedal sensor, a steering angle sensor, a yaw rate sensor, and a blade angle sensor. These sensors are configured to collect water depth information and vehicle speed information in real time, power demand information, steering angle information, and yaw rate information in real time, and blade deflection angle information in real time, respectively. The control unit is connected to the mechanical actuator and the sensing unit via a communication bus; The control unit internally stores a mode switching program for identifying the vehicle's driving environment, a driving control program for controlling the drive wheels to drive the vehicle and actively adjusting the mechanical actuators, and a control method for a wheel spoke variable structure for an amphibious vehicle, wherein: The mode switching program is used to identify whether the vehicle is currently in land driving mode or water floating mode. The travel control program is used to generate corresponding drive control commands and blade target angle control commands; The control unit sends control commands to the mechanical execution unit according to the control method to control the power source to drive the wheels on both sides at constant speed or differential speed, and controls the angle adjustment drive unit to drive the angle adjustment mechanism to synchronously adjust all the blades of the wheels to their respective target angles, so as to achieve efficient driving on land or flexible floating in water.

2. The spoke-variable structure drive wheel and control method for an amphibious vehicle according to claim 1, characterized in that, The angle adjustment mechanism can synchronously drive all the blades to rotate around their radial spoke axes. The angle adjustment mechanism includes: The system comprises a push-pull ring for connection to the angle adjustment drive unit via a ball joint, an outer spherical bearing with an interference fit to the half-shaft, a flange rotatably supported by the outer spherical bearing and the half-shaft, a disc-shaped component fixed to the flange, multiple connecting rods for connecting the blades and the disc-shaped component, a bearing assembly for rotatably supporting the push-pull ring, a pressure plate for pressing the bearing assembly, and a retaining ring for axially positioning the bearing assembly; the push-pull ring is mounted on the flange via the bearing assembly, such that the push-pull ring... The oscillation can be transmitted to the flange, while the push-pull ring does not rotate with the flange; the wheel end of each link is connected to one of the blades via a ball joint, and the body end is connected to the disc via a ball joint; when the angle adjustment drive unit drives the push-pull ring to oscillate, the push-pull ring deflects at a certain angle along the outer surface of the outer spherical bearing via the flange and the disc of the bearing assembly, thereby driving all blades to rotate synchronously around their respective spoke axes at unequal angles, realizing the dynamic adjustment of the blade angle with the wheel rotation angle.

3. The spoke-variable structure drive wheel and control method for an amphibious vehicle according to claim 1, characterized in that: The angle adjustment drive unit consists of a trapezoidal lead screw and nut mechanism, a drive motor for driving the trapezoidal lead screw, and a housing. The trapezoidal lead screw and nut mechanism has a self-locking function. The drive motor is fixedly mounted on the steering knuckle, and the output shaft of the drive motor is fixedly connected to the body end of the lead screw via a coupling. The housing is fixedly mounted on the steering knuckle.

4. The spoke-variable structure drive wheel and control method for an amphibious vehicle according to claim 1, characterized in that: The blade is a clip-on helical blade structure, consisting of blade one and blade two. Blade one and blade two are fixedly connected by bolts and nuts. After installation, the blade can rotate around the axis of the spokes. The blade is helical in shape. The cross-section of the blade is an airfoil section, and the thickness of the airfoil section in the middle is greater than the thickness at both ends. When the mode switching program identifies the vehicle as being in land driving mode, the generated blade target angle control command is used to adjust all blades to a fixed angle. ; When the mode switching program identifies the vehicle as being in water-floating mode, the generated propeller target angle control command is used to dynamically adjust the propeller angle according to the wheel rotation phase: that is, when the propeller rotates to its highest point, its angle is adjusted to... When the blades rotate to their lowest point, their angle is adjusted to... ; in, The The absolute angle of the tangent line at the center point of the intersection of the end face of blade one near the hub and the contact surface of blade two with respect to the end face of the hub.

5. The spoke-variable structure drive wheel and control method for an amphibious vehicle according to claim 1, characterized in that, The mode switching procedure is configured to perform the following functions: Continuously read water depth and vehicle speed information collected by water depth and vehicle speed sensors; Based on the water depth and vehicle speed information, determine whether the vehicle is currently in land driving mode or water-floating mode, specifically: If the water depth continues to exceed the water depth threshold and the vehicle speed is lower than the water entry speed threshold, the switching to the floating mode in the water will be triggered. If the water depth is lower than the exit water depth threshold, the switch to land driving mode will be triggered. The judgment result is output to the movement control program.

6. The spoke-variable structure drive wheel and control method for an amphibious vehicle according to claim 1, characterized in that, The travel control program is configured to execute the following control strategy based on the mode judgment result output by the mode switching program: In land driving mode, the drive control command controls the wheel rotation direction to adapt to the vehicle's driving direction, and the blade target angle control command controls the blade rotation angle of the left and right wheels to be consistent. In the floating mode, when the vehicle is traveling straight, the drive control command is for speed control, and the blade target angle control command is to control the blades of the left and right wheels to deflect in opposite directions and at equal angles. In the floating mode, when the vehicle turns or turns around, the drive control command is wheel differential compensation control, or controls the rotation direction of the left and right wheels to be opposite, and the blade target angle control command is blade differential angle compensation control; so that the two sides generate thrust of different magnitudes to form the steering torque required for different turning radii. The travel control procedure is also configured to perform the following controls: Speed ​​control: Based on the difference between the vehicle's actual speed and the target speed, the rotation speed of the left and right wheels is controlled to be the same, and both wheels rotate in the direction that generates thrust in the same direction as the direction of travel. The output torque of the drive wheels is dynamically adjusted to achieve closed-loop speed control. Wheel differential compensation control: Based on the vehicle's actual yaw rate and the target yaw rate obtained from the steering command in the running posture information, a differential compensation command for the left and right drive wheels is generated; according to the differential compensation command, the left and right drive wheels of the vehicle are controlled to rotate in the same direction at different speeds to assist the vehicle in turning on the water surface. Blade differential angle compensation control: Based on the actual yaw rate of the vehicle and the target yaw rate obtained from the steering command in the running attitude information, a differential angle compensation command for the left and right side angle adjustment drive unit of the vehicle is generated; according to the differential angle compensation command, the deflection angles of the blades of the left and right drive wheels of the vehicle are controlled to be opposite, and the target deflection angles of the blades of the left and right drive wheels of the vehicle are not equal, so as to assist the vehicle in turning on the water surface.

7. The spoke-variable structure drive wheel and control method for an amphibious vehicle according to claim 6, characterized in that, When the vehicle has a distributed drive architecture, meaning each wheel is driven by an independent power source, the specific execution steps of the control method are as follows: The system retrieves water depth sensor, vehicle speed sensor, accelerator pedal sensor, steering angle sensor, and yaw rate sensor from the sensing unit to continuously read vehicle operating environment information and vehicle operating attitude information. The environmental information includes water depth information and vehicle speed information, and the vehicle operating attitude information includes power demand information, steering angle information, and yaw rate information. The system then transmits the vehicle operating environment information to the mode switching program and the vehicle operating attitude information to the driving control program. The mode switching program is invoked. Based on the vehicle operating environment information read by the sensor unit, the mode switching program determines the current driving mode of the vehicle in real time and transmits the determination result to the driving control program. The driving control program is invoked, and based on the mode judgment result output by the received mode switching program and the vehicle running attitude information read by the sensor unit, the driver's intention is identified in real time. The control strategy is invoked to generate drive control commands and propeller target angle control commands. In the water-floating mode, when turning or making a U-turn, the wheel differential compensation control is mainly invoked to generate left and right wheel speed compensation commands, so that the left and right wheels rotate in the same direction at different speeds or rotate in opposite directions at the same speed, so that the two sides generate thrust of different magnitudes to form the required steering torque. After the command is executed, the blade angle sensor in the sensing unit is called to read the blade deflection angle information, and the information is continuously fed back to the mode switching program and the travel control program to form a closed-loop control.

8. The spoke-variable structure drive wheel and control method for an amphibious vehicle according to claim 6, characterized in that, When the vehicle has a centralized single-motor drive architecture, meaning the entire vehicle is driven by a single power source, the left and right wheels are mechanically connected via a differential. The specific execution steps of the control method are as follows: The system retrieves water depth sensor, vehicle speed sensor, accelerator pedal sensor, steering angle sensor, and yaw rate sensor from the sensing unit to continuously read vehicle operating environment information and vehicle operating attitude information. The environmental information includes water depth information and vehicle speed information, and the vehicle operating attitude information includes power demand information, steering angle information, and yaw rate information. The system then transmits the vehicle operating environment information to the mode switching program and the vehicle operating attitude information to the driving control program. The mode switching program is invoked. Based on the vehicle operating environment information read by the sensor unit, the mode switching program determines the current driving mode of the vehicle in real time and transmits the determination result to the driving control program. The driving control program is invoked, and based on the mode judgment result output by the received mode switching program and the vehicle running attitude information read by the sensor unit, the driver's intention is identified in real time, the corresponding control strategy is invoked, and drive control commands and blade target angle control commands are generated. In the control strategy, when turning or making a U-turn in the floating mode, since the centralized single motor drive cannot independently control the speed of the left and right wheels, the blade difference angle compensation control strategy is mainly invoked to generate blade deflection angle difference commands for the left and right wheels, so that the deflection angles of the blades on both sides are different, thereby generating thrust of different magnitudes to form the required steering torque. After the command is executed, the blade angle sensor in the sensing unit is called to read the blade deflection angle information, and the information is continuously fed back to the mode switching program and the travel control program to form a closed-loop control.

9. A spoke-variable structure drive wheel and control method for an amphibious vehicle according to claim 7 or 8, characterized in that, The control method also has the function of monitoring the drive current and position feedback of the drive motor of the angle adjustment drive unit during the blade angle adjustment process, including: If abnormal resistance or positional deviation is detected and continues to exceed the safety threshold, it is determined that the adjustment is blocked and a safety strategy is executed. The safety strategy includes stopping the adjustment, issuing an alarm, or attempting to return to a safe angle, where the safe angle is the target angle of the propeller when the vehicle is in land driving mode.

10. An amphibious vehicle, characterized in that, The amphibious vehicle includes the spoke-variable structure drive wheel and control method for amphibious vehicles as described in any one of claims 1-9.

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