A method, system and device for adaptive adjustment of optimal rotation speed of a screw-propelled vehicle

Abstract

The application discloses a spiral propelling vehicle optimal rotating speed self-adaptive adjustment method, system and device, and belongs to the spiral propelling vehicle field. Considering the actual operation condition of the spiral propelling vehicle, the rotating speed of the motor is continuously increased from a low rotating speed, current information is collected, and the rotating speed of the motor is comprehensively judged to be increased or decreased according to the influence of the resistance and the slip ratio of the spiral propelling vehicle, the rotating speed of the motor is self-adaptively adjusted after the optimal rotating speed range is found, and the rotating speed of the motor is controlled to be in the optimal rotating speed range. The optimal rotating speed which makes the influence of the resistance and the slip ratio on the spiral propelling vehicle running to be minimum is found, the spiral propelling vehicle is kept to stably work in the optimal rotating speed range, and the rotating speed of the spiral propelling vehicle is self-adaptively adjusted according to the actual working condition.

Description

Technical Field

[0001] This invention relates to the field of screw propulsion vehicles, and in particular to a method, system, and device for adaptively adjusting the optimal speed of a screw propulsion vehicle. Background Technology

[0002] The screw-propelled vehicle has a simple structure, is easy to control, travels at a uniform speed, has a large thrust, and excellent maneuverability, making it particularly suitable for working, traveling, and moving laterally in soft terrain such as swamps, lake beaches, and tidal flats. The screw-propelled vehicle uses a screw propeller as its traveling mechanism, achieving forward movement by changing the rotation directions of the left and right helical rollers. When the rollers rotate, the helical blades cut through the soil, and the forward thrust is generated through the friction between the roller blades and the soil.

[0003] Ground mechanics is one of the most important factors affecting the mobility of propeller vehicles. However, when operating in actual road conditions such as wetlands, the soil is not uniform, and the changes in soil mechanics are complex and difficult to predict. A fixed motor speed setting is insufficient to meet the needs of long-term operation. Moreover, the propulsion force of the propeller on wet and soft ground is affected by many factors such as the settlement of the propeller drum and the angle of entry and exit from the soil, making it difficult for the propeller vehicle to maintain stable operation over a long period. If the motor speed is set too low, the running gear will operate at insufficient speed, resulting in poor adaptability to different soil types. On the other hand, if the motor speed is set too high, it will not only lead to energy waste but may also increase the fatigue load on the motor and running gear components, reducing their service life. Summary of the Invention

[0004] The purpose of this invention is to provide a method, system, and device for adaptively adjusting the optimal speed of a propeller vehicle, which can adaptively adjust the speed of the propeller vehicle according to actual working conditions.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] An adaptive adjustment method for the optimal rotational speed of a propeller-driven vehicle includes:

[0007] The motor speed of the screw propulsion vehicle is increased sequentially from the initial idle speed to the first preset speed;

[0008] Each time the first preset rotation speed is increased, the resistance encountered by the propeller when it reaches a stable working state is obtained, and the difference between the resistance encountered by the propeller in the current stable working state and the previous stable working state is calculated.

[0009] If the resistance difference is less than or equal to the resistance difference threshold, the current motor speed is recorded, and the range of motor speeds with the minimum resistance is determined based on the current motor speed.

[0010] The motor speed of the screw propulsion vehicle is gradually reduced from the maximum value of the motor speed range to a second preset speed.

[0011] The slip ratio of the propeller vehicle when it reaches a stable working state after each reduction of the second preset speed is obtained, and the slip ratio of the propeller vehicle in two adjacent stable working states is compared.

[0012] The minimum motor speed in two adjacent stable operating states with the same slip ratio is determined as the optimal speed, and the optimal speed range is determined based on the optimal speed.

[0013] The motor speed of the propeller-driven vehicle is controlled to remain within the optimal speed range.

[0014] An optimal speed adaptive adjustment system for a propeller-driven vehicle includes:

[0015] The speed increase module is used to sequentially increase the motor speed of the screw propulsion vehicle from the initial idle speed to a first preset speed.

[0016] The resistance acquisition module is used to acquire the resistance experienced by the propeller when it reaches a stable working state after each increase of the first preset rotation speed, and to calculate the difference in resistance experienced by the propeller when it reaches the current stable working state and the previous stable working state.

[0017] The speed range determination module is used to record the current motor speed if the resistance difference is less than or equal to the resistance difference threshold, and determine the motor speed range with the minimum resistance based on the current motor speed.

[0018] The speed reduction module is used to sequentially reduce the motor speed of the screw propulsion vehicle from the maximum value of the motor speed range to a second preset speed.

[0019] The slip ratio acquisition module is used to acquire the slip ratio of the propeller vehicle when it reaches a stable working state after each reduction of the second preset speed, and to compare the slip ratio of the propeller vehicle in two adjacent stable working states.

[0020] The optimal speed range determination module is used to determine the minimum motor speed in two adjacent stable operating states with the same slip ratio as the optimal speed, and to determine the optimal speed range based on the optimal speed.

[0021] The control module is used to keep the motor speed of the propeller car within the optimal speed range.

[0022] An optimal speed adaptive adjustment device for a screw propulsion vehicle includes: a microcontroller;

[0023] The microcontroller is connected to the motor of the screw propulsion vehicle; the microcontroller is used to execute the above-mentioned optimal speed adaptive adjustment method of the screw propulsion vehicle, so that the motor speed of the screw propulsion vehicle is kept within the optimal speed range.

[0024] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0025] This invention discloses a method, system, and apparatus for adaptively adjusting the optimal speed of a screw propeller. Considering the actual operating conditions of the screw propeller, the method starts from a low speed and continuously increases the motor speed. It collects current information and comprehensively judges whether to increase or decrease the motor speed based on the influence of resistance and slippage on the screw propeller. After finding the optimal speed range, it adaptively adjusts the motor speed to control it within the optimal speed range. This invention achieves adaptive adjustment of the screw propeller speed according to actual operating conditions by finding the optimal speed that minimizes the impact of resistance and slippage on the screw propeller during operation, thus maintaining stable operation of the screw propeller within the optimal speed range. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic diagram of the forces acting on an existing spiral propulsion vehicle during straight-line travel; Figure 1 (a) in the diagram is a force diagram of the propeller-driven vehicle moving forward in a straight line. Figure 1 (b) in the diagram is a schematic diagram of the forces acting on the propeller vehicle as it moves forward in a straight line;

[0028] Figure 2 A schematic diagram of the forces acting on the lateral movement of an existing screw-propelled vehicle; Figure 2 (a) in the diagram shows the forces acting on the propeller vehicle as it moves to the right. Figure 2 (b) in the diagram is a force diagram of the screw propulsion vehicle moving to the left;

[0029] Figure 3 This is a schematic diagram of the forces acting on an existing screw-propelled vehicle during turning. Figure 3 (a) in the diagram is a force diagram of a screw-driven vehicle turning to the left. Figure 3 (b) in the diagram is a force diagram of the screw-driven vehicle turning right;

[0030] Figure 4 A flowchart illustrating an adaptive adjustment method for the optimal rotational speed of a screw propulsion vehicle, provided in an embodiment of the present invention;

[0031] Figure 5 A flowchart for calculating the resistance of a screw propulsion vehicle under stable operating conditions, provided in an embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of an adaptive adjustment method for the optimal rotational speed of a screw propulsion vehicle, provided in an embodiment of the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The purpose of this invention is to provide a method, system, and device for adaptively adjusting the optimal speed of a propeller vehicle, which can adaptively adjust the speed of the propeller vehicle according to actual working conditions.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] First, let's introduce the transmission method of the screw-propelled vehicle:

[0037] The propeller of a screw-driven vehicle typically consists of helical blades, a propeller housing, a drive motor, and seals. It employs a drive system where the motor directly rotates the drum. A microcontroller controls the motor to drive two helical propulsion devices with opposite rotation directions, changing the drum speed and direction to achieve straight-line travel, lateral movement, and turning on wet, soft surfaces.

[0038] like Figure 1 As shown, when the left and right spiral rollers rotate at the same speed (| |= | |) And when the rotation is opposite, the axial force of the left and right rollers = The forces are in the same direction and act on their respective axes. Lateral forces = The directions are opposite and act on the same straight line, enabling the vortex to move forward or backward.

[0039] like Figure 2 As shown, when the left and right spiral drums rotate at the same speed and in the same direction, the axial force is... = Lateral forces acting in opposite directions and on their respective axes = The directions are the same and they act on the same straight line, enabling the spiral to move left or right.

[0040] like Figure 3 As shown, when the speed of the left spiral drum is less than that of the right drum (| |<| |) And when the directions are the same, the axial force < They act in opposite directions and on their respective axes. Lateral forces < With the same direction and acting on the same straight line, the lawnmower can turn left, such as... Figure 3 (a) in the middle; similarly, when the left and right spiral rollers | |>| |And when the direction is the same, the lawnmower turns right, such as Figure 3 (b) in the middle.

[0041] Analysis of factors affecting the optimal rotational speed:

[0042] By analyzing the resistance and drum slippage rate encountered by the screw conveyor during operation, the optimal speed of the motor is found when the influence of resistance and drum slippage rate is minimized.

[0043] (1) Resistance

[0044] The propeller mainly overcomes soil resistance to move forward, and the resistance can be obtained from the following formula.

[0045]

[0046]

[0047]

[0048] In the formula:

[0049] For the torque of the screw conveyor drive motor, ;

[0050] The output power of the screw conveyor drive motor is expressed in W.

[0051] The rotational speed of the propeller is rpm;

[0052] The diameter of the spiral blades of the spiral drum is in mm;

[0053] F is the driving force of the helical blade, in N;

[0054] Let N be the resistance force experienced by the screw conveyor.

[0055] The driving force (N) for the screw conveyor to operate stably;

[0056] The driving force, N, is the driving force of the screw conveyor motor when it is idling.

[0057] (2) Slip ratio

[0058] After working in the soil for a period of time, the auger will reach a stable operating state, at which point the actual rotational speed of the drum will stabilize within a certain range. When the motor speed is low, the auger motor speed (idle speed) in a stable state is very close to the actual rotational speed of the auger. However, when the motor speed is too high, the actual rotational speed of the auger will decrease significantly. This is mainly because the propulsive force generated by the auger at high speeds is small and insufficient to resist soil resistance, easily causing the auger drum to slip, thus leading to a decrease in rotational speed. Therefore, the slip ratio i is introduced as a selection index for the auger rotational speed. The slip ratio can be obtained by the following formula.

[0059]

[0060]

[0061]

[0062] In the formula:

[0063] The theoretical forward speed of the propeller is given in m / s.

[0064] The actual forward speed of the propeller is m / s;

[0065] p represents the pitch of the screw roller blades of the screw conveyor, in mm;

[0066] The theoretical operating speed of the screw conveyor is rpm;

[0067] The actual operating speed of the screw conveyor is rpm;

[0068] The tip diameter of the propeller blades is in mm;

[0069] The helix angle is in degrees (°).

[0070] i represents the slip ratio of the spiral drum (°).

[0071] As can be seen from the above formulas, when the auger motor speed is low, the resistance it experiences during the stable operating phase is relatively large, requiring an increase in motor speed. However, once the auger speed reaches its optimal speed, further increasing the motor speed does not significantly change the resistance in the stable operating state. At this point, the slip ratio of the auger's traveling mechanism and the actual operating speed differ significantly from the theoretical operating speed, which can damage the drive motor over long periods. Therefore, this invention designs an adaptive adjustment method for the optimal speed of an auger propulsion vehicle. Considering the actual operating conditions of the auger, the method starts from a low speed and continuously increases the motor speed. It collects current information and comprehensively judges whether to increase or decrease the motor speed based on the resistance and slip ratio of the auger. After finding the optimal speed, the microcontroller adjusts the PWM duty cycle to adaptively adjust the motor speed, controlling it within the optimal speed range.

[0072] This invention provides an adaptive adjustment method for the optimal rotational speed of a screw propulsion vehicle, such as... Figure 4 As shown, it includes:

[0073] Step S1: Increase the speed of the motor of the screw propulsion vehicle from the initial idle speed to the first preset speed.

[0074] Step S2: After each increase of the first preset rotation speed, obtain the resistance encountered by the propeller when it reaches a stable working state, and calculate the difference in resistance encountered by the propeller between the current stable working state and the previous stable working state.

[0075] In one example, the resistance encountered by the propeller-driven vehicle when it reaches a stable operating state is obtained, specifically including:

[0076] Collect multiple actual rotational speeds of the spiral propulsion vehicle within a preset time period;

[0077] When the difference between the maximum and minimum actual rotational speed within a preset time period is less than the rotational speed fluctuation threshold, the propeller vehicle is determined to have reached a stable working state.

[0078] Based on the rotational speed of the screw propulsion vehicle under stable operating conditions, using formula F x =F w -F k Calculate the resistance F experienced by the propeller-driven vehicle when it reaches a stable operating state. x ;

[0079] Among them, F w F is the driving force for the stable operation of the propeller-driven vehicle. k This is the driving force for the motor of the screw propulsion vehicle when it is idling. , d represents the torque of the drive motor under stable operating conditions of the screw propulsion vehicle, and d represents the top diameter of the screw drum blades. This refers to the output power of the drive motor when the screw propulsion vehicle is operating stably. The rotational speed of the propeller vehicle under stable operating conditions.

[0080] Reference Figure 5 Taking the initial working state as an example, the resistance encountered by the propeller when it reaches a stable working state is obtained. The specific process is as follows: The propeller is set to an initial idle speed of r (rpm). After the speed fluctuation threshold m (the threshold is set according to the desired working speed), it enters the soil for operation. The microcontroller collects the current actual speed of the propeller from the Hall encoder of the motor every 50ms. Every 5s of speed collection, the microcontroller performs an analysis. When the actual speed fluctuation (maximum speed within 5s - minimum speed within 5s) < fluctuation threshold m (rpm), the propeller is considered to be in a stable working state. After reaching a stable working state, the resistance encountered by the propeller is calculated. .

[0081] Step S3: If the resistance difference is less than or equal to the resistance difference threshold, record the current motor speed and determine the motor speed range with the minimum resistance based on the current motor speed.

[0082] The motor speed range with the least resistance is (r0, r0+x); where r0 is the current motor speed and x is the first preset speed.

[0083] Before step S4, the method further includes: increasing the motor speed of the propeller vehicle to the maximum value of the motor speed range, and obtaining the slip ratio when the propeller vehicle reaches a stable working state.

[0084] Step S4: The motor speed of the screw propulsion vehicle is gradually reduced from the maximum value of the motor speed range to a second preset speed.

[0085] Step S5: Obtain the slip ratio of the propeller when it reaches a stable working state after each reduction of the second preset rotation speed, and compare the slip ratio of the propeller in two adjacent stable working states.

[0086] Step S6: Determine the minimum motor speed in two adjacent stable operating states with the same slip ratio as the optimal speed, and determine the optimal speed range based on the optimal speed.

[0087] The optimal speed range is (r-0.5m, r+0.5m); where r is the optimal speed.

[0088] Step S7: Control the motor speed of the propeller car to keep it within the optimal speed range.

[0089] In one example, the specific implementation process of step S7 is as follows:

[0090] When the propeller vehicle is in a stable working state, the microcontroller determines whether the current motor speed measurement value is within the optimal speed range and obtains the judgment result. If the judgment result indicates no, the motor speed is adjusted by the PWM duty cycle issued by the microcontroller to make the motor speed within the optimal speed range. If the judgment result indicates yes, the process ends.

[0091] Combination Figure 6 The overall principle of the adaptive adjustment method for the optimal speed of the screw propulsion vehicle provided by this invention is as follows:

[0092] 1. Initial operation: The auger is set to an initial idle speed of r (rpm). After a speed fluctuation threshold m (the threshold is set according to the desired working speed), it enters the soil for operation. The microcontroller collects the current actual speed of the auger from the motor's Hall encoder every 50ms. Every 5s of speed collection, the microcontroller performs an analysis. When the actual speed fluctuation (maximum speed within 5 seconds - minimum speed within 5 seconds) is less than the fluctuation threshold m (rpm), the auger is considered to be in a stable working state. After reaching a stable working state, the resistance currently experienced by the auger is calculated. And the slip ratio i of the spiral drum.

[0093] The microcontroller analyzes and judges the resistance encountered by the motor when it stabilizes again after the speed is increased. If the resistance difference is greater than the resistance difference threshold n, it means that the resistance is too large. The motor speed is increased by x (rpm) and the speed r is updated and compared again. If the resistance difference is less than the resistance difference threshold, the motor speed range with the minimum resistance is recorded as (r0, r0+x).

[0094] After increasing the motor speed by x once, the speed reaches r0+x. The slip ratio i of the auger is measured at this point. Then, the motor speed is decreased by y each time. Once a steady state is reached, the slip ratio i is compared to the previous value. If the slip ratio has decreased, a command is sent to the microcontroller to continue decreasing the motor speed r by y and update the current speed r. This process continues until the slip ratio no longer decreases in the steady operating state. The current speed r is recorded and considered the optimal speed (if the motor speed r drops below r0, then r0 is considered the optimal speed). The motor's adaptive speed is controlled by duty cycle adjustment within the range of r ± 0.5 m. In subsequent operations, this current motor speed r is set as the initial speed to quickly enter a stable operating state.

[0095] 2. Adaptive Phase: When the auger is operating stably, the microcontroller compares the current measured speed with the optimal speed value recorded by the microcontroller. If the speed deviation exceeds the set optimal speed range, the microcontroller adjusts the PWM duty cycle according to the program to control the motor speed, ensuring the speed remains within the optimal range. If the speed deviation is within the set deviation range, no adjustment is made. If the auger deviates from a stable operating state for a certain period, it will search for the optimal speed again.

[0096] Compared with the prior art, the present invention has the following advantages:

[0097] 1. The method of this invention is based on trial operation. During actual operation, the rotational speed of the screw drum is continuously increased to find the optimal speed that minimizes the impact of resistance and slippage on the screw conveyor's operation. PWM speed control is then used to adaptively adjust the speed, ensuring stable operation of the screw conveyor within the optimal speed range. This effectively improves the working efficiency of the screw conveyor, reduces fatigue load and energy consumption, and extends its service life.

[0098] 2. The field testing method of the present invention is applicable to all vehicles that use a propeller as a driving mechanism in different types of wetlands.

[0099] The present invention also provides an optimal speed adaptive adjustment system for a propeller-driven vehicle, comprising:

[0100] The speed increase module is used to sequentially increase the motor speed of the screw propulsion vehicle from the initial idle speed to a first preset speed.

[0101] The resistance acquisition module is used to acquire the resistance experienced by the propeller when it reaches a stable working state after each increase of the first preset rotation speed, and to calculate the difference in resistance experienced by the propeller when it reaches the current stable working state and the previous stable working state.

[0102] The speed range determination module is used to record the current motor speed if the resistance difference is less than or equal to the resistance difference threshold, and determine the motor speed range with the minimum resistance based on the current motor speed.

[0103] The speed reduction module is used to sequentially reduce the motor speed of the screw propulsion vehicle from the maximum value of the motor speed range to a second preset speed.

[0104] The slip ratio acquisition module is used to acquire the slip ratio of the propeller vehicle when it reaches a stable working state after each reduction of the second preset speed, and to compare the slip ratio of the propeller vehicle in two adjacent stable working states.

[0105] The optimal speed range determination module is used to determine the minimum motor speed in two adjacent stable operating states with the same slip ratio as the optimal speed, and to determine the optimal speed range based on the optimal speed.

[0106] The control module is used to keep the motor speed of the propeller car within the optimal speed range.

[0107] The optimal speed adaptive adjustment system for the propeller vehicle provided in this embodiment of the invention has a similar working principle and beneficial effects to the optimal speed adaptive adjustment method for the propeller vehicle described in the above embodiments, so it will not be described in detail here. For details, please refer to the introduction of the above method embodiments.

[0108] Furthermore, the present invention also provides an optimal speed adaptive adjustment device for a screw propeller, comprising: a microcontroller. The microcontroller is connected to the motor of the screw propeller; the microcontroller is used to execute the aforementioned optimal speed adaptive adjustment method for the screw propeller, so that the motor speed of the screw propeller is maintained within the optimal speed range.

[0109] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0110] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for adaptively adjusting the optimal rotational speed of a screw-propelled vehicle, characterized in that, include: The motor speed of the screw propulsion vehicle is increased sequentially from the initial idle speed to the first preset speed; Each time the first preset rotation speed is increased, the resistance encountered by the propeller when it reaches a stable working state is obtained, and the difference between the resistance encountered by the propeller in the current stable working state and the previous stable working state is calculated. If the resistance difference is less than or equal to the resistance difference threshold, the current motor speed is recorded, and the range of motor speeds with the minimum resistance is determined based on the current motor speed. The motor speed of the screw propulsion vehicle is gradually reduced from the maximum value of the motor speed range to a second preset speed. The slip ratio of the propeller vehicle when it reaches a stable working state after each reduction of the second preset speed is obtained, and the slip ratio of the propeller vehicle in two adjacent stable working states is compared. The minimum motor speed in two adjacent stable operating states with the same slip ratio is determined as the optimal speed, and the optimal speed range is determined based on the optimal speed. The motor speed of the propeller-driven vehicle is controlled to remain within the optimal speed range.

2. The adaptive adjustment method for the optimal rotational speed of a screw propulsion vehicle according to claim 1, characterized in that, The resistance encountered by the propeller vehicle when it reaches a stable operating state specifically includes: Collect multiple actual rotational speeds of the spiral propulsion vehicle within a preset time period; When the difference between the maximum and minimum actual rotational speed within a preset time period is less than the rotational speed fluctuation threshold, the propeller vehicle is determined to have reached a stable working state. Based on the rotational speed of the screw propulsion vehicle under stable operating conditions, using formula F x =F w -F k Calculate the resistance F experienced by the propeller-driven vehicle when it reaches a stable operating state. x ; Among them, F w F is the driving force for the stable operation of the propeller-driven vehicle. k This is the driving force for the motor of the screw propulsion vehicle when it is idling. , d represents the torque of the drive motor under stable operating conditions of the screw propulsion vehicle, and d represents the top diameter of the screw drum blades. This refers to the output power of the drive motor when the screw propulsion vehicle is operating stably. The rotational speed of the propeller vehicle under stable operating conditions.

3. The adaptive adjustment method for the optimal rotational speed of a screw propulsion vehicle according to claim 2, characterized in that, The formula for calculating the slip ratio is as follows: In the formula, i is the slip ratio of the spiral drum. The theoretical forward speed of the propulsion vehicle is... This represents the actual forward speed of the propulsion vehicle. The theoretical operating speed of the screw propulsion vehicle, denoted as the actual operating speed of the propeller, p is the pitch of the propeller drum blades, and φ is the helix angle.

4. The adaptive adjustment method for the optimal rotational speed of a screw-propelled vehicle according to claim 1, characterized in that, The range of motor speeds with the least resistance is (r0, r0+x); where r0 is the current motor speed and x is the first preset speed.

5. The adaptive adjustment method for the optimal rotational speed of a screw-propelled vehicle according to claim 1, characterized in that, The step of gradually decreasing the motor speed of the spiral propulsion vehicle from the maximum value of the motor speed range to a second preset speed includes, prior to: Increase the motor speed of the propeller vehicle to the maximum value of the motor speed range to obtain the slip ratio when the propeller vehicle reaches a stable working state.

6. The adaptive adjustment method for the optimal rotational speed of a screw-propelled vehicle according to claim 1, characterized in that, The optimal speed range is (r-0.5m, r+0.5m); where r is the optimal speed and m is the speed fluctuation threshold.

7. The adaptive adjustment method for the optimal rotational speed of a screw-propelled vehicle according to claim 1, characterized in that, The control of the motor speed of the spiral propulsion vehicle to maintain within the optimal speed range specifically includes: When the screw propulsion vehicle is in a stable working state, the microcontroller is used to determine whether the current motor speed measurement value is within the optimal speed range and obtain the judgment result. If the judgment result is negative, the motor speed is adjusted by the PWM duty cycle issued by the microcontroller to keep the motor speed within the optimal speed range; If the judgment result indicates yes, then the process ends.

8. An optimal speed adaptive adjustment system for a screw-propelled vehicle, characterized in that, include: The speed increase module is used to sequentially increase the motor speed of the screw propulsion vehicle from the initial idle speed to a first preset speed. The resistance acquisition module is used to acquire the resistance experienced by the propeller when it reaches a stable working state after each increase of the first preset rotation speed, and to calculate the difference in resistance experienced by the propeller when it reaches the current stable working state and the previous stable working state. The speed range determination module is used to record the current motor speed if the resistance difference is less than or equal to the resistance difference threshold, and determine the motor speed range with the minimum resistance based on the current motor speed. The speed reduction module is used to sequentially reduce the motor speed of the screw propulsion vehicle from the maximum value of the motor speed range to a second preset speed. The slip ratio acquisition module is used to acquire the slip ratio of the propeller vehicle when it reaches a stable working state after each reduction of the second preset speed, and to compare the slip ratio of the propeller vehicle in two adjacent stable working states. The optimal speed range determination module is used to determine the minimum motor speed in two adjacent stable operating states with the same slip ratio as the optimal speed, and to determine the optimal speed range based on the optimal speed. The control module is used to keep the motor speed of the propeller car within the optimal speed range.

9. An optimal speed adaptive adjustment device for a screw propulsion vehicle, characterized in that, include: Microcontroller; The microcontroller is connected to the motor of the screw propulsion vehicle; The microcontroller is used to execute the optimal speed adaptive adjustment method for the screw propulsion vehicle according to any one of claims 1-7, so that the motor speed of the screw propulsion vehicle is kept within the optimal speed range.

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