Motor quick response control method for zero-steering mowing vehicle and related device

Abstract

The invention relates to a motor quick response control method for a zero-steering mowing vehicle and a related device, and the method comprises the steps: building a dual-channel parallel processing logic for a left-side driving wheel and a right-side driving wheel, and obtaining an original target speed and an actual feedback speed corresponding to each channel; carrying out integral operation on the speed error between the original target speed and the actual feedback speed to generate target speed correction corresponding to each channel; performing superposition synthesis operation on the target speed correction and the original target speed to generate a dynamic target speed corresponding to each channel; and performing proportional operation according to an instant error between the dynamic target speed and the actual feedback speed, and generating a final control signal corresponding to each channel. The method has the advantages that integral operation is converted into active instruction guidance, the dynamic following capacity and response sensitivity of the zero-steering mowing vehicle are improved, and meanwhile the overshoot phenomenon is avoided so that the vehicle running stability can be guaranteed.

Description

Technical Field

[0001] This application relates to the field of garden machinery, and in particular to a method and device for rapid response control of a motor for a zero-steering lawnmower. Background Technology

[0002] Zero-steering lawnmowers are widely used in the field of garden machinery. They achieve flexible steering and straight-line driving primarily through the independent speed difference between the left and right drive wheels. Therefore, accurate speed control of the motors on both drive wheels is fundamental to ensuring that the lawnmower's trajectory matches expectations and improving the user experience. Current drive control systems typically employ a dual-channel independent control architecture, acquiring target speed commands and actual feedback speeds for the left and right wheels respectively.

[0003] In existing speed closed-loop control, the industry commonly uses the classic proportional-integral (PI) controller as the core regulator. The traditional PI controller works by subtracting the target speed from the actual feedback speed to obtain the instantaneous error. The proportional term then linearly amplifies this instantaneous error, while the integral term calculates the historical accumulation of this error and outputs its result. Finally, the outputs of the proportional and integral terms are added together to form the final control signal for the drive motor.

[0004] Zero-steering lawnmowers, due to their significant weight and frequent operation on unpaved surfaces with varying resistance, such as grass, exhibit substantial mechanical inertia. In this working environment, traditional control architectures reveal inherent contradictions. To accelerate the system's response during start-up or acceleration, a larger proportional gain is typically required. However, this can lead to noticeable overshoot as the system approaches the target speed, causing vehicle vibration or instability.

[0005] Conversely, if the proportional gain is reduced to ensure smooth driving and more reliance is placed on the integral term to eliminate steady-state error, the initial driving force of the system will be insufficient in the early stages when the speed command changes, as the integral term requires a longer time to accumulate errors. In practice, this manifests as integral lag, characterized by slow start-up and insufficient dynamic following ability. When the driver frequently accelerates, decelerates, or turns, this sluggish response not only reduces the lawnmower's operational efficiency but may also lead to asynchronous speed adjustments in the left and right wheels, affecting the accuracy of the lawnmower's trajectory. Summary of the Invention

[0006] In order to improve the speed response sensitivity of a zero-steering lawnmower under varying operating conditions without compromising the stability of the control system, and to solve the balance problem between response speed and overshoot resistance in traditional control architectures, this application provides a fast response control method and related device for a motor in a zero-steering lawnmower.

[0007] Firstly, this application provides a fast-response control method for a motor in a zero-steering lawnmower, employing the following technical solution: A fast-response control method for a motor in a zero-steering lawnmower includes: S1. Establish a dual-channel parallel processing logic for the left and right drive wheels, and obtain the original target speed and actual feedback speed for each channel respectively; S2. Based on the real-time operating conditions, calculate the difference between the original target speed and the actual feedback speed in each channel to obtain the speed error, and perform an integral operation on the speed error to update the integral accumulation value, thereby generating the target speed correction amount corresponding to each channel. The real-time operating conditions include emergency reset operating conditions, saturation obstruction operating conditions, steering differential operating conditions, or conventional variable coefficient operating conditions. S3. The target speed correction amount corresponding to each channel is superimposed and synthesized with the original target speed to generate the dynamic target speed corresponding to each channel; S4. Calculate the instantaneous error between the dynamic target speed corresponding to each channel and the actual feedback speed corresponding to each channel, and perform proportional calculation based on the instantaneous error corresponding to each channel to generate the final control signal corresponding to each channel.

[0008] Optionally, step S2 includes the following sub-steps: S21. Obtain the control status data of the zero-steering lawnmower, and determine whether it is in emergency reset condition, saturation obstruction condition, steering differential condition or normal variable coefficient condition based on the control status data. S22. In response to the emergency reset condition, execute the forced zeroing logic and output the target speed correction amount with a value of zero; S23. In response to the saturated and obstructed working condition, execute the integral clamping logic and output the target speed correction amount, which is equal to the preset correction amount saturation extreme value; S24. In response to the steering differential condition, execute the steering decoupling logic and output the target speed correction amount corresponding to each channel; S25. In response to the conventional variable coefficient operating condition, execute the variable integral coefficient logic and output the target speed correction amount calculated based on the dynamic integral coefficient.

[0009] Optionally, S22 includes the following sub-steps: S221. Extract the original target speed corresponding to each channel in the current operation cycle, the original target speed corresponding to each channel in the previous operation cycle, and the actual feedback speed corresponding to each channel in the current operation cycle. S222. Calculate the difference between the original target speed corresponding to each channel in the current operation cycle and the original target speed corresponding to each channel in the previous operation cycle, and obtain the target speed change rate corresponding to each channel; S223. Determine whether the rate of change of the target speed corresponding to each channel is less than a preset emergency braking negative threshold, or determine whether the product of the original target speed corresponding to each channel in the current calculation cycle and the original target speed corresponding to each channel in the previous calculation cycle is less than zero. S224. When the target speed change rate corresponding to each channel is less than the preset emergency braking negative threshold or the product of the original target speed corresponding to each channel in the current calculation cycle and the original target speed corresponding to each channel in the previous calculation cycle is less than zero, a forced zeroing command is triggered to directly overwrite the accumulated integral value corresponding to each channel with zero. S225. Output the target speed correction amount corresponding to each channel with a value of zero.

[0010] Optionally, step S23 includes the following sub-steps: S231. Calculate the difference between the original target speed corresponding to each channel and the actual feedback speed corresponding to each channel to obtain the speed error corresponding to each channel; S232. Determine whether the speed error corresponding to each channel is greater than a preset error threshold, and determine whether the duration of the speed error corresponding to each channel being greater than the preset error threshold exceeds a preset time threshold; S233. When the conditions are met that the speed error corresponding to each channel is greater than the preset error threshold and the duration exceeds the preset time threshold, stop performing the integral accumulation operation for the speed error corresponding to each channel, and clamp the integral accumulation value corresponding to each channel to the preset correction saturation extreme value. S234. Output the target velocity correction amount corresponding to each channel whose value is equal to the saturation extreme value of the correction amount.

[0011] Optionally, S24 includes the following sub-steps: S241. Extract the original target speed of the left wheel corresponding to the corresponding channel of the left drive wheel and the original target speed of the right wheel corresponding to the corresponding channel of the right drive wheel in the dual-channel parallel processing logic, and extract the actual feedback speed of the left wheel corresponding to the corresponding channel of the left drive wheel and the actual feedback speed of the right wheel corresponding to the corresponding channel of the right drive wheel; S242. Calculate the left wheel speed error between the original target speed of the left wheel and the actual feedback speed of the left wheel, and the right wheel speed error between the original target speed of the right wheel and the actual feedback speed of the right wheel, respectively; S243. Calculate the absolute value of the difference between the original target speed of the left wheel and the original target speed of the right wheel, and obtain the steering differential command value; S244. Based on the steering differential command value, lower the preset base integral coefficient corresponding to the inner turning channel to obtain the lowered integral coefficient; wherein, the inner turning channel is the channel corresponding to the drive wheel with the smaller absolute value between the original target speed of the left wheel and the original target speed of the right wheel; S245. Based on the reduced integral coefficient, perform integral calculations independently for the left wheel speed error and the right wheel speed error, and output the left wheel target speed correction amount and the right wheel target speed correction amount as the target speed correction amount corresponding to each channel.

[0012] Optionally, S25 includes the following sub-steps: S251. Calculate the difference between the original target speed and the actual feedback speed corresponding to each channel, and obtain the absolute value of the speed error; S252. The absolute value of the speed error is compared with a preset first error interval and a preset second error interval, respectively, wherein the lower limit of the first error interval is greater than the upper limit of the second error interval, and the difference between the lower limit of the first error interval and the upper limit of the second error interval is defined as the transition error interval. S253. When the absolute value of the speed error falls into the first error interval, a preset first integral coefficient is used to perform an integral operation on the speed error; when the absolute value of the speed error falls into the second error interval, a preset second integral coefficient with a value greater than the first integral coefficient is used to perform an integral operation on the speed error; when the absolute value of the speed error falls into the transition error interval, a smooth transition integral coefficient is used to perform an integral operation on the speed error. S254. Based on the first integral coefficient, the second integral coefficient, or the smooth transition integral coefficient, perform the integral operation for the speed error and output the calculated target speed correction amount.

[0013] Optionally, S244 includes the following sub-steps: S2441. Extract the basic integral coefficient, the preset maximum permissible steering differential value, and the preset maximum steering attenuation ratio; S2442. Calculate the ratio between the steering differential command value and the maximum permissible steering differential value to obtain the steering aggression factor; S2443. Multiply the steering abruptness factor by the maximum steering attenuation ratio to obtain the dynamic attenuation coefficient; S2444. Calculate the difference between value 1 and the dynamic attenuation coefficient to obtain the attenuation multiplier; multiply the basic integral coefficient by the attenuation multiplier to generate the adjusted integral coefficient corresponding to the inner channel of the turn.

[0014] Optionally, step S253 includes the following sub-steps: S2531. When the absolute value of the speed error falls into the first error interval, extract the first integral coefficient and call the first integral coefficient to perform an integral operation on the speed error; S2532. When the absolute value of the speed error falls into the second error range, extract the second integral coefficient and call the second integral coefficient to perform an integral operation on the speed error; S2533. Determine whether the absolute value of the speed error falls within the transition error interval located between the first error interval and the second error interval; S2534. When the absolute value of the speed error falls into the transition error interval, a linear interpolation operation is performed between the first integral coefficient and the second integral coefficient according to the numerical proportion of the absolute value of the speed error within the transition error interval to obtain a smooth transition integral coefficient. S2535. Invoke the smooth transition integral coefficient to perform an integral operation on the speed error.

[0015] Secondly, this application provides a speed-response control system for a zero-steering lawnmower, which adopts the following technical solution: A speed-response control system for a zero-steering lawnmower includes: Target speed setting module; The left and right speed sensors are respectively located on the left and right drive wheels; A left motor drive module and a right motor drive module respectively drive the left drive wheel and the right drive wheel; The PI controller includes a target speed dynamic adjustment module and a proportional adjustment module.

[0016] Thirdly, the zero-steering lawnmower provided in this application adopts the following technical solution: A zero-steering lawnmower, employing the speed fast response control system described above for zero-steering lawnmowers.

[0017] In summary, this application includes at least one of the following beneficial technical effects: 1. This application generates a target speed correction by integrating the speed error, and then superimposes the target speed correction with the original target speed to form a dynamic target speed. Subsequently, proportional adjustment is performed based on the instantaneous error of the dynamic target speed. This architecture transforms the integral calculation into proactive command guidance, enabling the system to react instantly to the raised dynamic target speed during start-up or initial changes in target speed, outputting a larger drive signal and effectively improving the system's dynamic following capability and response sensitivity. Simultaneously, because the dynamic target speed undergoes integral smoothing, it avoids system oscillations or overshoot caused by simply increasing the proportional coefficient, ensuring the smoothness of the lawnmower's operation.

[0018] 2. This application establishes a dual-channel parallel processing logic for the left and right drive wheels of a zero-steering lawnmower, and adjusts the integral coefficient of the inner turning channel according to the steering differential command value under steering differential conditions. This control strategy conforms to the physical kinematic characteristics of dual-wheel differential steering, preventing the inner driving wheel from overshooting due to excessive integral accumulation during turning, thereby maintaining the speed adjustment synchronization rate of the left and right wheels, ensuring that the actual steering trajectory of the lawnmower accurately matches the expected turning radius, and improving the overall steering control accuracy.

[0019] 3. This application introduces underlying adaptive logic based on control state data, including targeted handling mechanisms for emergency reset conditions, saturation-impeded conditions, and normal variable coefficient conditions. In avoidance scenarios where the target speed drops sharply, the system immediately cancels the integral guidance by triggering a forced zeroing command, ensuring the execution priority of the braking command. In high-resistance-impeded conditions, the system prevents loss of power control when the vehicle is out of trouble by continuously accumulating the integral clamping stop error. During normal driving, the system switches the integral coefficient in different error ranges, balancing the control requirements of smooth start-up and eliminating steady-state static error, effectively enhancing the system's robustness and operational safety in variable physical environments. Attached Figure Description

[0020] Figure 1 A flowchart illustrating a method for rapid motor response control of a zero-steering lawnmower according to an embodiment of the present invention is shown. Detailed Implementation

[0021] The present application will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the application and are not intended to limit the scope of the application.

[0022] This application discloses a fast-response control method for a motor in a zero-steering lawnmower, referring to... Figure 1 , including S1-S4.

[0023] S1. Establish dual-channel parallel processing logic for the left and right drive wheels, and obtain the original target speed and actual feedback speed for each channel respectively.

[0024] S2. Based on the real-time operating conditions, calculate the difference between the original target speed and the actual feedback speed in each channel to obtain the speed error, and perform an integral operation on the speed error to update the integral accumulation value, thereby generating the target speed correction amount corresponding to each channel. The real-time operating conditions include emergency reset operating conditions, saturation obstruction operating conditions, steering differential operating conditions, or conventional variable coefficient operating conditions.

[0025] S3. The target speed correction amount corresponding to each channel is superimposed and synthesized with the original target speed to generate the dynamic target speed corresponding to each channel.

[0026] S4. Calculate the instantaneous error between the dynamic target speed corresponding to each channel and the actual feedback speed corresponding to each channel, and perform proportional calculation based on the instantaneous error corresponding to each channel to generate the final control signal corresponding to each channel.

[0027] The dual-channel parallel processing logic for the aforementioned control method is based on the fact that the zero-steering lawnmower eliminates the traditional steering mechanical axle structure, relying instead on the independent speed difference between the left and right drive wheels to achieve straight-line driving and steering. Applying the dual-channel parallel processing logic to the zero-steering lawnmower ensures the kinematic control of the left and right drive wheels is decoupled, thereby improving the vehicle's trajectory control accuracy on unpaved roads. In each control channel, the initial target speed refers to the desired driving command received by the control system, typically obtained through analog-to-digital conversion of the mechanical displacement of the driver's push lever; the actual feedback speed refers to the current physical speed of the drive wheels, usually acquired in real-time by speed sensors mounted on the motor or drive shaft.

[0028] After obtaining the aforementioned speed parameters, the control system enters the error calculation and integral operation stage. The mathematical model of a traditional proportional-integral controller is as follows: ,in For the final control signal, This represents the fixed deviation between the original target speed and the actual feedback speed. This traditional structure calculates the proportional and integral terms in parallel and then adds them directly. When dealing with the large mechanical inertia of a lawnmower, this often leads to integral lag or proportional overshoot.

[0029] This embodiment breaks with this parallel architecture. The microprocessor within the system allocates independent threads and underlying registers to the left and right control channels respectively, and extracts the original target speed for the current computation cycle through dual-thread parallel computation. With actual feedback speed Calculate the difference between the two to obtain the speed error. The microprocessor then calls the set integral coefficient. Regarding speed error Perform time-dimensional integration, accumulating the single-step increment into the corresponding integration accumulator register to generate independent target speed correction values ​​for each channel. Its mathematical expression is During the numerical accumulation process, for example, when the original target speed is set to 5 kilometers per hour and the actual feedback speed is 0 kilometers per hour, the speed error is 5 kilometers per hour. In the first operation cycle, the microprocessor extracts this error and calculates the increment using the integral coefficient, stores it in a register with an initial value of zero, and outputs a target speed correction amount greater than zero. In subsequent control cycles, as long as the actual feedback speed does not reach the original target speed, the value in the register will continue to increase.

[0030] After generating the target velocity correction, the control logic enters the superposition and synthesis stage. The system will continuously adjust the target velocity correction. Superimposed on the original target velocity Above, generate dynamic target speed Its mathematical expression is This process transforms traditional passive error compensation into active command guidance, creating a virtual tracking target that is higher than the original command. During the initial acceleration phase, assuming the original target speed is constant at 5 kilometers per hour, as the integral calculation continues, the target speed correction accumulates to 0.5 kilometers per hour within a set time. After superposition and synthesis, the actual dynamic target speed being tracked by the system is increased to 5.5 kilometers per hour, creating a clear numerical difference from the constant original target speed.

[0031] Furthermore, the distinction of instantaneous error lies in the fact that its comparison benchmark is not the original target velocity, but the synthesized dynamic target velocity. The microprocessor calculates the dynamic target velocity. With actual feedback speed instantaneous error between Its mathematical expression is The control system calls the proportional coefficient based on this instantaneous error. Perform single-item proportional calculations to generate the final control signal. Compared to traditional proportional-integral (PI) control architectures, this embodiment places the integral calculations at the beginning, embedding the integral result into the target setting stage. Because the dynamic target speed is pre-increased during the initial acceleration phase, the instantaneous error is amplified synchronously, allowing the proportional calculation stage to instantly generate a larger final control signal without altering the underlying hardware parameters. This control signal directly drives the motor to overcome the system's mechanical inertia, shortening the response time for the zero-steering lawnmower to reach the set speed. Simultaneously, leveraging the smooth accumulation characteristics of the integral value, it avoids the oscillations caused by directly increasing the proportional coefficient.

[0032] To visually demonstrate the difference in response time between the control method in this embodiment and the traditional proportional-integral control scheme, a complete example is provided here. The initial target speed is set to a constant 5 meters per second, with a proportional coefficient of 2 and an integral coefficient of 0.5. Parameters at multiple rate nodes are compared during the complete process of a zero-steering lawnmower accelerating from a standstill to a steady state.

[0033] At the initial moment when the actual feedback speed is 0 meters per second, the time taken by both the traditional solution and the solution in this embodiment is 0 seconds. At this time, the speed error is 5 meters per second, and the integral accumulation is 0. The final control signal of the traditional solution is 10. In the solution of this embodiment, the cumulative amount of the target speed dynamic adjustment module performing integral calculation is 0, the target speed correction amount is 0, the dynamic target speed is 5 meters per second, the instantaneous error is 5 meters per second, and the final control signal is also 10.

[0034] In the initial acceleration phase, where the actual feedback speed reaches 1.0 meter per second, the traditional scheme takes 0.25 seconds, while the scheme in this embodiment takes 0.23 seconds. At 0.25 seconds, the speed error of the traditional scheme is 4 meters per second, the integral accumulation is approximately 1.13, and the final control signal is 8.56. At 0.23 seconds, the speed error of the scheme in this embodiment is 4 meters per second, the integral accumulation is approximately 1.05, the target speed correction is 0.52, the dynamic target speed increases to 5.52 meters per second, the instantaneous error is 4.52 meters per second, and the final control signal output is 9.04.

[0035] In the acceleration phase where the actual feedback speed reaches 2.0 meters per second, the traditional solution takes 0.65 seconds, while the solution in this embodiment takes 0.58 seconds. At 0.65 seconds, the speed error of the traditional solution is 3 meters per second, the integral accumulation is approximately 2.53, and the final control signal is 7.26. At 0.58 seconds, the speed error of the solution in this embodiment is 3 meters per second, the integral accumulation is approximately 2.27, the target speed correction is 1.13, the dynamic target speed increases to 6.13 meters per second, the instantaneous error is 4.13 meters per second, and the final control signal output is 8.26.

[0036] During the continuous acceleration phase where the actual feedback speed reaches 3.0 meters per second, the traditional solution takes 1.80 seconds, while the solution in this embodiment takes 1.25 seconds. At 1.80 seconds, the speed error of the traditional solution is 2 meters per second, the integral accumulation is approximately 5.32, and the final control signal is 6.66. At 1.25 seconds, the speed error of the solution in this embodiment is 2 meters per second, the integral accumulation is approximately 3.92, the target speed correction is 1.96, the dynamic target speed rises to 6.96 meters per second, the instantaneous error is 3.96 meters per second, and the final control signal output is 7.92.

[0037] When the actual feedback speed reaches 4.0 meters per second, the traditional solution takes 6.80 seconds, while the solution in this embodiment takes 3.10 seconds. At 6.80 seconds, the speed error of the traditional solution is 1 meter per second, the integral accumulation is approximately 12.51, and the final control signal is 8.25. At 3.10 seconds, the speed error of the solution in this embodiment is 1 meter per second, the integral accumulation only needs to reach 6.57, the target speed correction is 3.28, the dynamic target speed is raised to 8.28 meters per second, the instantaneous error is 4.28 meters per second, and the final control signal output is 8.56.

[0038] In the steady-state phase where the actual feedback speed reaches 4.9 meters per second, the traditional scheme takes 24.0 seconds, while the scheme in this embodiment takes 11.0 seconds. At 24.0 seconds, the speed error of the traditional scheme is 0.1 meters per second, the integral accumulation is approximately 19.26, and the final control signal is approximately 10.0. At 11.0 seconds, the speed error of the scheme in this embodiment is 0.1 meters per second, the integral accumulation is approximately 9.66, the target speed correction is 4.83, the dynamic target speed rises to 9.83 meters per second, the instantaneous error is 4.93 meters per second, and the final control signal output is approximately 10.0.

[0039] Through the calculation and comparison of the above multiple rate nodes, it can be seen that the solution in this embodiment, through pre-integral operation and proportional amplification mechanism, reduces the time for the zero-steering lawnmower to reach the set steady-state speed from 24.0 seconds to 11.0 seconds while maintaining the consistency of the final steady-state control signal, thereby shortening the system response time of the whole vehicle.

[0040] Optionally, S2 includes the following sub-steps S21-S25.

[0041] S21. Obtain the control status data of the zero-steering lawnmower, and determine whether it is in emergency reset condition, saturation obstruction condition, steering differential condition or normal variable coefficient condition based on the control status data.

[0042] In this step, the control status data specifically includes the original target speed for the current and historical calculation cycles, the actual feedback speed for the current calculation cycle, the duration for which the speed error exceeds the threshold, and the steering differential command value between the left and right drive wheels. This data is acquired by the microprocessor within the PI controller periodically reading the real-time input signals sent by the target speed setting module and the speed sensor via an internal communication bus, while simultaneously retrieving historical speed data from the previous calculation cycle from the microprocessor's cache register.

[0043] The purpose of introducing a condition determination step as a pre-routing branch system is to resolve the conflict problem that a single integral control strategy cannot adapt to various complex operating conditions. Zero-steering lawnmowers face different working states when operating on grass, such as starting, emergency braking, obstacle crossing, or turning in place. The pre-routing branch system allows the microprocessor to pre-calculate the vehicle's actual operating condition based on state data characteristics before executing specific integral calculations and accumulations. Based on the determination result, the microprocessor distributes subsequent control signal calculation logic to the corresponding specific processing branch. For example, when the microprocessor routes the system to the emergency reset condition branch, the system will directly block the integral accumulation path under the normal variable coefficient condition, preventing the integral calculation result under normal conditions from interfering with the operator's emergency braking action. This pre-distribution mechanism ensures the accurate triggering and independent operation of various specific condition control logics.

[0044] S22. In response to the emergency reset condition, execute the forced zeroing logic and output the target speed correction amount with a value of zero.

[0045] When encountering sudden hazard avoidance scenarios triggering emergency reset conditions, executing the forced zeroing logic has engineering significance in ensuring the safety of equipment and personnel. During normal start-up or acceleration phases, the target speed correction amount provides positive drive gain to the motor drive module through continuous accumulation. When the driver suddenly pulls the operating lever back to the zero position or the reverse position to perform emergency braking, if the system continues to retain the target speed correction amount accumulated in the previous calculation cycle, this correction amount will be superimposed on the suddenly dropped original target speed, resulting in a slow decrease in dynamic target speed. This phenomenon will generate drive torque opposite to the braking command direction in the initial stage of braking, weakening the reverse braking signal output by the proportional adjustment module and extending the physical braking distance of the lawnmower. Therefore, the target speed correction amount with an output value of zero can eliminate the negative offsetting effect of integral residue on braking action, helping the system restore the highest braking priority.

[0046] Optionally, S22 includes the following sub-steps S221-S225.

[0047] S221. Extract the original target speed corresponding to each channel in the current operation cycle, the original target speed corresponding to each channel in the previous operation cycle, and the actual feedback speed corresponding to each channel in the current operation cycle. S222. Calculate the difference between the original target speed corresponding to each channel in the current operation cycle and the original target speed corresponding to each channel in the previous operation cycle, and obtain the target speed change rate corresponding to each channel; S223. Determine whether the rate of change of the target speed corresponding to each channel is less than a preset emergency braking negative threshold, or determine whether the product of the original target speed corresponding to each channel in the current calculation cycle and the original target speed corresponding to each channel in the previous calculation cycle is less than zero. S224. When the target speed change rate corresponding to each channel is less than the preset emergency braking negative threshold or the product of the original target speed corresponding to each channel in the current calculation cycle and the original target speed corresponding to each channel in the previous calculation cycle is less than zero, a forced zeroing command is triggered to directly overwrite the accumulated integral value corresponding to each channel with zero. S225. Output the target speed correction amount corresponding to each channel with a value of zero.

[0048] The operation cycle refers to the fixed time interval within the PI controller's microprocessor that completes one full data sampling and logic calculation. Extracting the historical target speed from the previous operation cycle is the fundamental condition for constructing differential calculations to evaluate speed changes. The control system subtracts the historical target speed from the current operation cycle's original target speed to obtain the target speed change rate. This rate directly reflects the driver's intention to decelerate by operating the push lever. To identify emergency braking operations, the system pre-sets an emergency braking negative threshold, calibrated based on the deceleration of the lawnmower within the safe operating boundary at zero steering speed. For example, the emergency braking negative threshold is set to a decrease of 3 meters per second. When the lawnmower is traveling at 5 meters per second, if the driver pulls back the push lever within one operation cycle, causing the original target speed to drop sharply to 1 meter per second, the calculated target speed change rate is a decrease of 4 meters per second. Since the value -4 is less than -3, satisfying the condition that the target speed change rate is less than the preset emergency braking negative threshold, the system immediately determines the current operation as an emergency braking action.

[0049] Simultaneously, the system determines whether the product of the original target speed in the current calculation cycle and the original target speed in the previous calculation cycle is less than zero, utilizing the mathematical theorem that the product of two numbers with opposite signs is negative. When the system detects that the product is less than zero, it means that the sign of the original target speed has been reversed, corresponding to the driver's sudden reversing action of pulling the lever from the forward gear directly past the stop position to the reverse gear. Once any of the above conditions are met, the high-priority interrupt service routine inside the microprocessor will be triggered, directly writing an absolute zero value to the underlying hardware register storing the accumulated integral value, thus erasing the historical integral. In actual comparative verification, assuming the zero-steering lawnmower is traveling at a speed of 5 meters per second and encounters a sudden obstacle, the vehicle without a forced zeroing mechanism has a physical braking distance of 3.5 meters because the residual integral offsets the initial braking torque; while the vehicle with this mechanism outputs reverse braking torque within the first control cycle after the emergency braking is detected, shortening the physical braking distance to 1.8 meters, effectively improving the braking performance of the entire vehicle in avoidance scenarios.

[0050] S23. In response to the saturated and obstructed operating condition, execute the integral clamping logic and output the target speed correction amount, which is equal to the preset correction amount saturation extreme value.

[0051] The specific manifestation of saturated resistance is that the actual feedback speed is consistently much lower than the original target speed. In physical obstacle scenarios for zero-steering lawnmowers, such as when the vehicle drives into a deep pit, gets stuck in muddy terrain, or the drive wheels are blocked by obstacles, the drive motor will encounter significant mechanical resistance. In this case, even if the system continues to output drive torque, the actual feedback speed may still be close to zero.

[0052] To address this situation, the fundamental control principle of integral clamping logic lies in interrupting the unlimited accumulation process of integral operations. In conventional proportional-integral (PI) control, as long as the speed error persists, the integral term will continuously increase over time. When the system enters an abnormally obstructed state, the integral clamping logic actively freezes the numerical changes in the integral accumulation register to prevent internal numerical overflow, thereby providing safety protection for the control system.

[0053] The preset correction saturation extreme value is set based on the maximum safe overload current of the motor drive module and the rated torsional strength calibration of the mechanical transmission components. The system limits the maximum upper limit of the target speed correction at this extreme value, which has the safety significance of preventing power surge. When the lawnmower is in an obstructed state, an unrestricted target speed correction will cause the dynamic target speed to be abnormally high, thereby increasing the heat generation of the motor and exceeding the design margin of the mechanical structure.

[0054] A comparative analysis is conducted based on the aforementioned scenario where the initial target speed is set to a constant 5 meters per second and the integral coefficient is 0.5. Assume a lawnmower with zero steering gets stuck in a deep pit, and the actual feedback speed drops to 0 meters per second, remaining stuck for 5 seconds. Without the integral clamping logic, the speed error of 5 meters per second would cause the integral to accumulate continuously, reaching a target speed correction of 12.5 meters per second after 5 seconds. If the vehicle suddenly crosses the pit and escapes, the actual physical resistance drops sharply, and the system's synthesized dynamic target speed would instantly reach 17.5 meters per second. This would result in an abnormally large instantaneous error value, causing the vehicle to accelerate forward excessively, potentially leading to loss of control. In the scheme implementing the integral clamping logic, the system clamps the target speed correction at a preset correction saturation extreme value in the early stages of the stuck situation, for example, setting it to 2 meters per second. When the vehicle escapes, the dynamic target speed is only a maximum of 7 meters per second, and the final control signal generated by the proportional calculation is limited to a controllable and safe range, avoiding power loss of control at the moment of escape.

[0055] Optionally, S23 includes the following sub-steps S231-S234.

[0056] S231. Calculate the difference between the original target speed corresponding to each channel and the actual feedback speed corresponding to each channel to obtain the speed error corresponding to each channel; S232. Determine whether the speed error corresponding to each channel is greater than a preset error threshold, and determine whether the duration of the speed error corresponding to each channel being greater than the preset error threshold exceeds a preset time threshold; S233. When the conditions are met that the speed error corresponding to each channel is greater than the preset error threshold and the duration exceeds the preset time threshold, stop performing the integral accumulation operation for the speed error corresponding to each channel, and clamp the integral accumulation value corresponding to each channel to the preset correction saturation extreme value. S234. Output the target velocity correction amount corresponding to each channel whose value is equal to the saturation extreme value of the correction amount.

[0057] For the above sub-steps, the preset error threshold is set based on the maximum permissible slip ratio of the zero-steering lawnmower under normal cutting operations and the system's steady-state tracking capability. When the calculated speed error exceeds the preset error threshold, it indicates that the drive wheels have encountered mechanical resistance beyond the normal operating range, causing the motor to be unable to follow the set speed command.

[0058] The purpose of introducing a preset time threshold and a preset error threshold for dual judgment is to filter out transient terrain interference. When a zero-steering lawnmower travels on unpaved roads, the drive wheels often run over stones or short potholes, causing the actual feedback speed to drop sharply in a short period of time and produce significant error fluctuations. If only the error value is used for a single judgment, the system will frequently trigger integral clamping, interfering with the normal power compensation process. By setting a preset time threshold, the microprocessor only recognizes a situation as a true trapped state when the speed error exceeds the limit and persists, thereby filtering out the interference of brief terrain undulations on the control logic.

[0059] The smooth transition mechanism of the dynamic target speed at the moment the vehicle overcomes the obstacle is based on a reasonable limitation of the target speed correction. Following the aforementioned settings, the original target speed is constant at 5 meters per second, and the system's preset correction saturation limit is set at 2 meters per second. When the vehicle is stuck in a deep pit for a period exceeding a preset time threshold, the microprocessor stops integrating and outputs a target speed correction of 2 meters per second. At this point, the system-synthesized dynamic target speed is limited to 7 meters per second. When the zero-steering lawnmower crosses the pit and returns to normal road conditions, the actual feedback speed rapidly increases as resistance decreases. Because the dynamic target speed does not accumulate indefinitely and remains stable at 7 meters per second, the instantaneous error calculated by the microprocessor gradually decreases as the actual feedback speed increases. The proportional adjustment module synchronously reduces the output of the final control signal based on the gradually decreasing instantaneous error, guiding the actual feedback speed to smoothly fall back and re-align with the original target speed of 5 meters per second, ensuring a smooth transition during the vehicle's escape phase.

[0060] S24. In response to the steering differential condition, execute the steering decoupling logic and output the target speed correction amount corresponding to each channel.

[0061] The specific triggering condition for the steering differential condition is that the control system receives the original target speeds on the left and right sides, which have a difference. In terms of physical kinematics, this condition covers a zero-steering lawnmower performing a U-turn by turning one wheel forward while the other wheel turns backward, as well as a large-angle steering action by turning both wheels in the same direction but with a speed difference.

[0062] The purpose of steering decoupling logic is to break the synchronous integral compensation of the left and right drive wheels during normal straight-line driving, allowing the microprocessor to assign different integral control weights to the two sides. This logic is essential in a dual-wheel independent drive architecture. Without steering decoupling logic, both wheels accumulate errors using equal integral coefficients when turning. Since the initial target speed of the inner wheel is lower, these equal integral coefficients cause the inner wheel's integral accumulation to be too rapid. This interference causes the inner wheel's actual feedback speed to exceed the preset low-speed target, thus reducing the actual speed difference between the left and right wheels. Ultimately, this results in the zero-steering lawnmower's actual trajectory deviating outwards from the predetermined turning radius.

[0063] Optionally, S24 includes the following sub-steps S241-S245.

[0064] S241. Extract the original target speed of the left wheel corresponding to the corresponding channel of the left drive wheel and the original target speed of the right wheel corresponding to the corresponding channel of the right drive wheel in the dual-channel parallel processing logic, and extract the actual feedback speed of the left wheel corresponding to the corresponding channel of the left drive wheel and the actual feedback speed of the right wheel corresponding to the corresponding channel of the right drive wheel.

[0065] S242. Calculate the left wheel speed error between the original target speed of the left wheel and the actual feedback speed of the left wheel, and the right wheel speed error between the original target speed of the right wheel and the actual feedback speed of the right wheel.

[0066] S243. Calculate the absolute value of the difference between the original target speed of the left wheel and the original target speed of the right wheel to obtain the steering differential command value.

[0067] S244. Based on the steering differential command value, lower the preset basic integral coefficient corresponding to the inner turning channel to obtain the lowered integral coefficient; wherein, the inner turning channel is the channel corresponding to the drive wheel with the smaller absolute value between the original target speed of the left wheel and the original target speed of the right wheel.

[0068] In the above sub-steps, the data flow of the independently extracted speed parameters on the left and right sides is represented by the microprocessor reading the control commands and feedback states of both sides in parallel through independent data buses. The original target speed of the left wheel and the original target speed of the right wheel correspond to the displacement sensor signals at the bottom of the left and right hand operating levers, respectively, while the actual feedback speed of the left wheel and the actual feedback speed of the right wheel correspond to the speed sensor signals installed on the output shafts of the left and right drive motors, respectively.

[0069] The principle behind calculating the steering differential command value is to subtract the desired speeds of the left and right wheels and take the absolute value. This value directly reflects the vehicle's currently set steering curvature. The larger the difference, the smaller the turning radius desired by the driver. In the same amount of time, the arc traced by the inner wheel during a turn will inevitably be shorter than that of the outer wheel, thus requiring a lower physical linear velocity.

[0070] Lowering the base integral coefficient on the inside of the turn is to prevent speed overshoot. By reducing the integral coefficient of the inside channel, the control system actively slows down the growth rate of the target speed correction on the inside, ensuring that the actual feedback speed of the inside drive wheel strictly follows the lower original target speed, maintaining a stable steering differential ratio.

[0071] Specifically, S244 includes the following sub-steps S2441-S2444.

[0072] S2441. Extract the basic integral coefficient, the preset maximum permissible steering differential value, and the preset maximum steering attenuation ratio.

[0073] S2442. Calculate the ratio between the steering differential command value and the maximum permissible steering differential value to obtain the steering aggression factor.

[0074] S2443. Multiply the steering abruptness factor by the maximum steering attenuation ratio to obtain the dynamic attenuation coefficient.

[0075] S2444. Calculate the difference between value 1 and the dynamic attenuation coefficient to obtain the attenuation multiplier; multiply the basic integral coefficient by the attenuation multiplier to generate the adjusted integral coefficient corresponding to the inner channel of the turn.

[0076] The maximum permissible steering differential value is an engineering parameter calibrated at the factory based on the wheelbase width and the limit safe yaw rate of a zero-steering lawnmower. It represents the vehicle's highest differential capability without rollover. The maximum steering attenuation ratio is a pre-set lower limit to prevent the inner integral coefficient from dropping to zero during a turn. The mathematical model for constructing the steering aggression factor divides the current real-time steering differential command value by the fixed maximum permissible steering differential value. This calculation step normalizes the data, mapping the specific physical speed difference to a dimensionless proportional value between 0 and 1.

[0077] The dynamic attenuation coefficient establishes a linkage between the degree of integral attenuation and the real-time changes in the driver's operating range. As the difference between the left and right push levers increases, the dynamic attenuation coefficient increases linearly proportionally. The difference between the calculated value 1 and the dynamic attenuation coefficient is used to obtain the attenuation multiplier, which transforms the attenuation effect into a specific multiplication factor. Multiplying the basic integral coefficient by this attenuation multiplier ensures that even in extreme steering conditions such as a U-turn on the spot, the inner wheel retains some integral calculation capability to overcome the static friction of the ground, ensuring that the inner wheel has basic error correction capability.

[0078] To explain the calculation process of the reduced integral coefficient in detail, a base integral coefficient of 0.5 is set, the maximum permissible steering differential is 10 meters per second, and the maximum steering attenuation ratio is 0.8. When the original target speed of the left wheel is set to 2 meters per second and the original target speed of the right wheel is set to 6 meters per second, the microprocessor determines that the left side with the smaller absolute value is the inner turning lane. The steering differential command value is calculated to be 4 meters per second. Dividing 4 meters per second by 10 meters per second yields a steering aggression factor of 0.4. Multiplying 0.4 by the maximum steering attenuation ratio of 0.8 yields a dynamic attenuation coefficient of 0.32. Subtracting 0.32 from the value of 1 yields an attenuation multiplier of 0.68. Finally, multiplying the base integral coefficient of 0.5 by the attenuation multiplier of 0.68, the reduced integral coefficient for the left inner turning lane is calculated to be 0.34. The right outer turning lane continues to use the base integral coefficient of 0.5 for subsequent calculations.

[0079] S245. Based on the reduced integral coefficient, perform integral calculations independently for the left wheel speed error and the right wheel speed error, and output the left wheel target speed correction amount and the right wheel target speed correction amount as the target speed correction amount corresponding to each channel.

[0080] When performing the above steps, the reduced integral coefficient clearly suppressed the growth curve of the target speed correction for the inner wheel during the turn. Because the integral coefficient of the left control channel decreased from 0.5 to 0.34, the integral increment stored in the register by the microprocessor in each operation cycle decreased, assuming the same speed error value. This made the slope of the target speed correction for the inner wheel during the left turn more gradual over time. Compared to the state without the reduced coefficient, this suppression limited the increase in the dynamic target speed of the inner wheel, preventing the inner drive wheel from obtaining excessively high drive gain during the initial stages of starting or accelerating into a turn.

[0081] This control strategy, which suppresses the correction of the inner target speed, forms a physical closed loop that maintains a high degree of consistency between the actual driving trajectory and the expected turning radius. Continuing with the aforementioned turning condition where the original target speed of the left wheel is 2 meters per second and the original target speed of the right wheel is 6 meters per second, the driver sets a fixed expected turning radius by inputting this set of speed commands. If the left lane continues to use a base integral coefficient of 0.5, during the acceleration and turning phase, the rapid accumulation of integrals will cause the dynamic target speed of the left wheel to quickly become too high, causing the actual feedback speed of the left wheel to exceed the original target of 2 meters per second, for example, overshooting to 3 meters per second. At this time, the actual speed difference between the left and right wheels shrinks from the expected 4 meters per second to 3 meters per second, and the actual driving trajectory of the zero-steering lawnmower will shift outwards, resulting in a larger turning radius. In this embodiment, by lowering the left integral coefficient to 0.34, the increase in the dynamic target speed of the left wheel is strictly limited, stabilizing the actual feedback speed of the left wheel at 2 meters per second. Simultaneously, the right drive wheel accelerates normally to 6 meters per second under the guidance of the base integral coefficient of 0.5. The left and right wheels precisely replicated the set speed difference, ensuring that the vehicle completed the turning maneuver according to the expected turning radius.

[0082] S25. In response to the conventional variable coefficient operating condition, execute the variable integral coefficient logic and output the target speed correction amount calculated based on the dynamic integral coefficient.

[0083] The specific criteria for determining the normal variable coefficient operating condition are that the control system does not receive an emergency braking command, does not detect that the drive wheels are obstructed, and the original target speed values ​​of the left and right control channels are equal. This operating condition corresponds to the normal driving performance of a zero-steering lawnmower in daily lawn maintenance operations, such as straight-line start, smooth acceleration, smooth deceleration, and constant speed cruising.

[0084] In conventional control systems, using a fixed integral coefficient presents an inherent physical contradiction between preventing overshoot and eliminating steady-state static error. If a large fixed integral coefficient is set, the system can quickly accumulate integral data to overcome mechanical resistance and eliminate static error in the steady-state phase. However, during the initial acceleration phase, when facing a large initial speed deviation, a large coefficient can lead to excessively rapid integral accumulation, causing overshoot where the actual vehicle speed exceeds the set desired speed. Conversely, if a small fixed integral coefficient is set, while it can suppress overshoot in the initial acceleration phase, the system may not be able to output sufficient driving torque to offset mechanical friction resistance as it approaches the target speed, ultimately leaving behind an unavoidable steady-state static error.

[0085] The core definition of variable integral coefficient logic lies in the fact that the microprocessor dynamically allocates different integral control weights by evaluating the real-time speed deviation. This mechanism allocates lower weights during periods of large error and higher weights during periods of small error, thus resolving the contradiction that a single fixed coefficient cannot simultaneously achieve smooth start-up and steady-state accuracy.

[0086] Optionally, S25 includes the following sub-steps S251-S254.

[0087] S251. Calculate the difference between the original target speed and the actual feedback speed corresponding to each channel, and obtain the absolute value of the speed error.

[0088] S252. The absolute value of the speed error is compared with a preset first error interval and a preset second error interval, wherein the lower limit of the first error interval is greater than the upper limit of the second error interval, and the difference between the lower limit of the first error interval and the upper limit of the second error interval is defined as the transition error interval.

[0089] S253. When the absolute value of the speed error falls into the first error interval, a preset first integral coefficient is invoked to perform an integral operation on the speed error; when the absolute value of the speed error falls into the second error interval, a preset second integral coefficient with a value greater than the first integral coefficient is invoked to perform an integral operation on the speed error; when the absolute value of the speed error falls into the transition error interval, a smooth transition integral coefficient is invoked to perform an integral operation on the speed error.

[0090] In the aforementioned sub-steps, the control logic using the absolute value of the speed error as the judgment criterion can ignore the difference in the sign of the operation command direction. Whether it's a positive speed deviation caused by forward acceleration or a negative speed deviation caused by backward movement, the microprocessor extracts its absolute magnitude for a unified interval comparison, achieving unified compatibility of the underlying control logic for acceleration and deceleration scenarios. The first error interval physically represents a significant numerical difference between the current actual vehicle speed and the desired vehicle speed, corresponding to the stage of rapid acceleration with large errors caused by vehicle start-up or the driver's large-scale push-pull operation of the lever. In this stage, the microprocessor calls the first integral coefficient with a smaller value within the first error interval. This anti-overshoot mechanism strictly limits the integral accumulation step size within a single calculation cycle, suppressing a sudden increase in the target speed correction amount in a short period, and preventing excessive accumulation of correction values ​​in the early stages from leading to loss of vehicle speed control later.

[0091] In contrast, the second error interval represents the current actual physical vehicle speed, which is very close to the desired speed, corresponding to the small error steady-state stage at the end of the acceleration process. At this time, the microprocessor calls a second integral coefficient with a value greater than the first integral coefficient. Since the error value itself is already very small, the larger second integral coefficient can quickly multiply and accumulate this small error to generate a sufficient target speed correction. This steady-state error elimination mechanism provides the drive module with additional compensation instructions to counteract the friction within the chassis's mechanical transmission components and the viscous resistance of the grass, forcing the actual physical vehicle speed to perfectly match the original target speed.

[0092] The purpose of setting a transition error range in control theory is to provide a buffer zone for parameter switching by the microprocessor. If the microprocessor performs abrupt, direct switching between the first and second error ranges, the jump in the integral coefficient will cause a step change in the control command. A smooth transition integral coefficient connects the two error ranges through continuous numerical changes. This mechanism eliminates current spikes within the motor drive module at the physical execution level, prevents sudden changes in the output torque of the drive motor, and ensures a smooth transition of the lawnmower through different acceleration phases.

[0093] In the specific settings of the engineering implementation, the lower limit of the first error interval is set to 2.0 meters per second, and the upper limit of the second error interval is set to 0.5 meters per second. At this point, the speed deviation range greater than 2.0 meters per second is defined as the first error interval; the speed deviation range less than 0.5 meters per second is defined as the second error interval; and the speed deviation range between 0.5 meters per second and 2.0 meters per second naturally forms the transition error interval. The system precisely controls the timing of the invocation of various integral coefficients through this specific numerical range.

[0094] Specifically, S253 includes the following sub-steps S2531-S2535.

[0095] S2531. When the absolute value of the speed error falls into the first error interval, extract the first integral coefficient and call the first integral coefficient to perform an integral operation on the speed error.

[0096] S2532. When the absolute value of the speed error falls into the second error range, extract the second integral coefficient and call the second integral coefficient to perform an integral operation on the speed error.

[0097] S2533. Determine whether the absolute value of the speed error falls within the transition error interval located between the first error interval and the second error interval.

[0098] S2534. When the absolute value of the speed error falls into the transition error interval, a linear interpolation operation is performed between the first integral coefficient and the second integral coefficient according to the numerical proportion of the absolute value of the speed error within the transition error interval to obtain a smooth transition integral coefficient.

[0099] S2535. Invoke the smooth transition integral coefficient to perform an integral operation on the speed error.

[0100] In linear interpolation, the mathematical model involves constructing a continuous straight line equation between two known coordinate points to solve for the unknown variable within the interval. When applying this method to smooth the transition of variables in this embodiment, the microprocessor uses the boundary value of the first error interval and the first integral coefficient as one known coordinate point, and the boundary value of the second error interval and the second integral coefficient as another known coordinate point. By performing linear interpolation, the system establishes an inverse mapping relationship between the numerical proportion of the absolute value of the velocity error within the transition error interval and the magnitude of the generated dynamic integral coefficient. This inverse mapping relationship manifests as follows: as the absolute value of the velocity error gradually decreases and approaches the boundary of the second error interval from the boundary of the first error interval, the smooth transition integral coefficient calculated by the microprocessor gradually increases linearly.

[0101] Based on the aforementioned engineering parameters, the lower limit of the first error interval is set to 2.0 meters per second, with a corresponding first integral coefficient of 0.5. The upper limit of the second error interval is set to 0.5 meters per second, with a corresponding second integral coefficient of 2.0. The transition error interval is then defined as between 0.5 meters per second and 2.0 meters per second. Assuming the actual feedback speed extracted in the current calculation cycle is 4.0 meters per second, while the original target speed is a constant 5.0 meters per second, the calculated absolute value of the speed error is 1.0 meter per second. The microprocessor determines that this value falls within the transition error interval and then performs linear interpolation. The microprocessor calculates the difference between 1.0 meters per second and 2.0 meters per second, then divides it by the difference between 0.5 meters per second and 2.0 meters per second to obtain the specific numerical ratio. This numerical ratio is multiplied by the difference between the second and first integral coefficients, i.e., 1.5. Finally, the product is added to the first integral coefficient of 0.5 to deduce the complete value of the smooth transition integral coefficient for the current calculation cycle, which is 1.5.

[0102] S254. Based on the first integral coefficient, the second integral coefficient, or the smooth transition integral coefficient, perform the integral operation for the speed error and output the calculated target speed correction amount.

[0103] In the complete data flow of a conventional variable-coefficient operating condition, the control system first detects the original target speed and the actual feedback speed through sensors and a setting module, and then calculates the difference within the microprocessor to obtain the speed error for the current calculation cycle. Subsequently, the microprocessor executes interval determination and coefficient combination logic. For example, when the absolute value of the speed error is 1.0 meter per second, the microprocessor extracts a smooth transition integral coefficient of 1.5. Next, the microprocessor multiplies this smooth transition integral coefficient with the speed error of 1.0 meter per second to obtain the integral single-step increment for that control cycle, and accumulates this increment into the integral accumulation register of the underlying hardware. After completing the accumulation, the microprocessor extracts the latest value from the register and outputs it directly as the target speed correction to the next stage of the calculation link, participating in the subsequent superposition and synthesis calculation of the dynamic target speed.

[0104] In another embodiment, this application further discloses a speed-response control system for a zero-steering lawnmower, comprising: Target speed setting module; The left and right speed sensors are respectively located on the left and right drive wheels; A left motor drive module and a right motor drive module respectively drive the left drive wheel and the right drive wheel; The PI controller includes a target speed dynamic adjustment module and a proportional adjustment module, which are used to execute the motor fast response control method for a zero-steering lawnmower as described in the previous embodiment.

[0105] In another embodiment, this application further discloses a speed-response control system for a zero-steering lawnmower, as described above.

[0106] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0107] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0108] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for rapid response control of a motor in a zero-steering lawnmower, characterized in that, include: S1. Establish a dual-channel parallel processing logic for the left and right drive wheels, and obtain the original target speed and actual feedback speed for each channel respectively; S2. Based on the real-time operating conditions, calculate the difference between the original target speed and the actual feedback speed in each channel to obtain the speed error, and perform an integral operation on the speed error to update the integral accumulation value, thereby generating the target speed correction amount corresponding to each channel. The real-time operating conditions include emergency reset operating conditions, saturation obstruction operating conditions, steering differential operating conditions, or conventional variable coefficient operating conditions. S3. The target speed correction amount corresponding to each channel is superimposed and synthesized with the original target speed to generate the dynamic target speed corresponding to each channel; S4. Calculate the instantaneous error between the dynamic target speed corresponding to each channel and the actual feedback speed corresponding to each channel, and perform proportional calculation based on the instantaneous error corresponding to each channel to generate the final control signal corresponding to each channel.

2. The method for rapid motor response control of a zero-steering lawnmower according to claim 1, characterized in that, S2 includes the following sub-steps: S21. Obtain the control status data of the zero-steering lawnmower, and determine whether it is in emergency reset condition, saturation obstruction condition, steering differential condition or normal variable coefficient condition based on the control status data. S22. In response to the emergency reset condition, execute the forced zeroing logic and output the target speed correction amount with a value of zero; S23. In response to the saturated and obstructed working condition, execute the integral clamping logic and output the target speed correction amount, which is equal to the preset correction amount saturation extreme value; S24. In response to the steering differential condition, execute the steering decoupling logic and output the target speed correction amount corresponding to each channel; S25. In response to the conventional variable coefficient operating condition, execute the variable integral coefficient logic and output the target speed correction amount calculated based on the dynamic integral coefficient.

3. The method for rapid motor response control of a zero-steering lawnmower according to claim 2, characterized in that, S22 includes the following sub-steps: S221. Extract the original target speed corresponding to each channel in the current operation cycle, the original target speed corresponding to each channel in the previous operation cycle, and the actual feedback speed corresponding to each channel in the current operation cycle. S222. Calculate the difference between the original target speed corresponding to each channel in the current operation cycle and the original target speed corresponding to each channel in the previous operation cycle, and obtain the target speed change rate corresponding to each channel; S223. Determine whether the rate of change of the target speed corresponding to each channel is less than a preset emergency braking negative threshold, or determine whether the product of the original target speed corresponding to each channel in the current calculation cycle and the original target speed corresponding to each channel in the previous calculation cycle is less than zero. S224. When the target speed change rate corresponding to each channel is less than the preset emergency braking negative threshold or the product of the original target speed corresponding to each channel in the current calculation cycle and the original target speed corresponding to each channel in the previous calculation cycle is less than zero, a forced zeroing command is triggered to directly overwrite the accumulated integral value corresponding to each channel with zero. S225. Output the target speed correction amount corresponding to each channel with a value of zero.

4. The method for rapid motor response control of a zero-steering lawnmower according to claim 2, characterized in that, S23 includes the following sub-steps: S231. Calculate the difference between the original target speed corresponding to each channel and the actual feedback speed corresponding to each channel to obtain the speed error corresponding to each channel; S232. Determine whether the speed error corresponding to each channel is greater than a preset error threshold, and determine whether the duration of the speed error corresponding to each channel being greater than the preset error threshold exceeds a preset time threshold; S233. When the conditions are met that the speed error corresponding to each channel is greater than the preset error threshold and the duration exceeds the preset time threshold, stop performing the integral accumulation operation for the speed error corresponding to each channel, and clamp the integral accumulation value corresponding to each channel to the preset correction saturation extreme value. S234. Output the target velocity correction amount corresponding to each channel whose value is equal to the saturation extreme value of the correction amount.

5. The method for rapid motor response control of a zero-steering lawnmower according to claim 2, characterized in that, S24 includes the following sub-steps: S241. Extract the original target speed of the left wheel corresponding to the corresponding channel of the left drive wheel and the original target speed of the right wheel corresponding to the corresponding channel of the right drive wheel in the dual-channel parallel processing logic, and extract the actual feedback speed of the left wheel corresponding to the corresponding channel of the left drive wheel and the actual feedback speed of the right wheel corresponding to the corresponding channel of the right drive wheel; S242. Calculate the left wheel speed error between the original target speed of the left wheel and the actual feedback speed of the left wheel, and the right wheel speed error between the original target speed of the right wheel and the actual feedback speed of the right wheel, respectively; S243. Calculate the absolute value of the difference between the original target speed of the left wheel and the original target speed of the right wheel, and obtain the steering differential command value; S244. Based on the steering differential command value, lower the preset base integral coefficient corresponding to the inner turning channel to obtain the lowered integral coefficient; wherein, the inner turning channel is the channel corresponding to the drive wheel with the smaller absolute value between the original target speed of the left wheel and the original target speed of the right wheel; S245. Based on the reduced integral coefficient, perform integral calculations independently for the left wheel speed error and the right wheel speed error, and output the left wheel target speed correction amount and the right wheel target speed correction amount as the target speed correction amount corresponding to each channel.

6. The method for rapid motor response control of a zero-steering lawnmower according to claim 2, characterized in that, S25 includes the following sub-steps: S251. Calculate the difference between the original target speed and the actual feedback speed corresponding to each channel, and obtain the absolute value of the speed error; S252. The absolute value of the speed error is compared with a preset first error interval and a preset second error interval, respectively, wherein the lower limit of the first error interval is greater than the upper limit of the second error interval, and the difference between the lower limit of the first error interval and the upper limit of the second error interval is defined as the transition error interval. S253. When the absolute value of the speed error falls into the first error interval, a preset first integral coefficient is used to perform an integral operation on the speed error; when the absolute value of the speed error falls into the second error interval, a preset second integral coefficient with a value greater than the first integral coefficient is used to perform an integral operation on the speed error; when the absolute value of the speed error falls into the transition error interval, a smooth transition integral coefficient is used to perform an integral operation on the speed error. S254. Based on the first integral coefficient, the second integral coefficient, or the smooth transition integral coefficient, perform the integral operation for the speed error and output the calculated target speed correction amount.

7. The method for rapid motor response control of a zero-steering lawnmower according to claim 5, characterized in that, S244 includes the following sub-steps: S2441. Extract the basic integral coefficient, the preset maximum permissible steering differential value, and the preset maximum steering attenuation ratio; S2442. Calculate the ratio between the steering differential command value and the maximum permissible steering differential value to obtain the steering aggression factor; S2443. Multiply the steering abruptness factor by the maximum steering attenuation ratio to obtain the dynamic attenuation coefficient; S2444. Calculate the difference between value 1 and the dynamic attenuation coefficient to obtain the attenuation multiplier; multiply the basic integral coefficient by the attenuation multiplier to generate the adjusted integral coefficient corresponding to the inner channel of the turn.

8. The method for rapid motor response control of a zero-steering lawnmower according to claim 6, characterized in that, S253 includes the following sub-steps: S2531. When the absolute value of the speed error falls into the first error interval, extract the first integral coefficient and call the first integral coefficient to perform an integral operation on the speed error; S2532. When the absolute value of the speed error falls into the second error interval, extract the second integral coefficient and call the second integral coefficient to perform an integral operation on the speed error; S2533. Determine whether the absolute value of the speed error falls within the transition error interval located between the first error interval and the second error interval; S2534. When the absolute value of the speed error falls into the transition error interval, a linear interpolation operation is performed between the first integral coefficient and the second integral coefficient according to the numerical proportion of the absolute value of the speed error within the transition error interval to obtain a smooth transition integral coefficient. S2535. Invoke the smooth transition integral coefficient to perform an integral operation on the speed error.

9. A speed-response control system for a zero-steering lawnmower, characterized in that, include: Target speed setting module; The left and right speed sensors are respectively located on the left and right drive wheels; A left motor drive module and a right motor drive module respectively drive the left drive wheel and the right drive wheel; A PI controller, which includes a target speed dynamic adjustment module and a proportional adjustment module, is used to execute the motor fast response control method for a zero-steering lawnmower as described in any one of claims 1 to 8.

10. A zero-steering lawnmower, characterized in that, The application uses the speed-response control system for a zero-steering lawnmower as described in claim 9.

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