Walking control system and method of mower

Abstract

The invention discloses a walking control system of a mowing machine, which comprises a walking assembly comprising a walking wheel and a motor for driving the walking wheel to walk; the operation assembly comprises a speed control part and controls the motor to rotate according to a speed signal given by the speed control part; when the operation assembly obtains the change degree of movement of the speed control part, the target rotating speed corresponding to the motor is obtained in a nonlinear speed regulation mode, and the operation assembly controls the motor to rotate according to the target rotating speed. According to the mower, the stability of the mower in the walking process can be effectively guaranteed, abrasion to parts of the mower is reduced, and the service life of the mower is prolonged.

Description

Technical Field

[0001] The present invention relates to a walking control system, and in particular to a walking control system and method for a lawn mower. Background Art

[0002] A lawn mower, a mechanical tool used for trimming lawns and vegetation, consists of a cutterhead, motor, wheels, a running mechanism, blades, handrails, and controls. The high-speed rotation of the motor significantly increases the blade's output speed, significantly saving time and manpower. Currently, lawn mowers have evolved into a variety of styles, including mounted mowers, drum mowers, and rotary mowers. To further reduce the operator's workload, riding mowers also offer the option of a ride-on system.

[0003] Chinese patent document CN112740892B discloses a riding lawn mower, comprising: a power output assembly including a mowing element, a cutting motor for driving the mowing element, and a cutting control module for controlling the cutting motor; a travel assembly including travel wheels, a travel motor for driving the travel wheels, and a travel control module for controlling the travel motor; a first operating assembly for setting a start mode for the travel motor, the first operating assembly having: a first operating state for enabling the travel motor to start in a first start mode, in which the travel motor starts at a first start acceleration; a second operating state for enabling the travel motor to start in a second start mode, in which the travel motor starts at a second start acceleration; the second start acceleration being greater than the first start acceleration. The riding lawn mower of the present invention has multiple operating modes, can meet the diverse needs of users, and provides a good user experience.

[0004] This prior art solves the technical problem that conventional riding lawn mowers have only one fixed starting acceleration mode, which fails to meet user needs. However, when riding lawn mowers are capable of switching between multiple speeds, the speed changes during switching can easily lead to unstable operation and increased wear on components. Summary of the Invention

[0005] In order to solve the technical problem that a lawn mower in the prior art is prone to unstable travel, the present invention provides a travel control system for the lawn mower, comprising:

[0006] A traveling assembly, comprising a traveling wheel and a motor for driving the traveling wheel;

[0007] An operating component includes a speed control component and controls the rotation of the motor according to a speed signal given by the speed control component;

[0008] When the operating component obtains the degree of change in the movement of the speed control component, it uses a nonlinear speed regulation method to obtain the target speed corresponding to the motor, and the operating component controls the motor to rotate according to the target speed.

[0009] In existing technologies, when a lawn mower's travel speed changes, it is prone to excessive impact, resulting in unstable travel and wear. In this solution, a nonlinear speed regulation method is used to achieve speed changes. This means that when the lawn mower's speed changes, it changes gradually rather than suddenly. Therefore, even when the speed changes during travel, the operating component can control the motor speed to gradually change from the current speed to the target speed, making the movement smoother and more fluid. This reduces the impact on the lawn mower, effectively ensures the stability of the lawn mower during travel, reduces the wear on the lawn mower's components, and increases the lawn mower's service life.

[0010] Preferably, when the operating component performs nonlinear speed regulation, the obtained change degree is calculated according to formula ① to obtain the target speed corresponding to the motor.

[0011] targetSpeed=maxSpeed*f(x)……Formula ①;

[0012] Where targetSpeed ​​represents the target speed, maxSpeed ​​represents the preset maximum forward speed or maximum reverse speed; f(x) is calculated according to formula ②:

[0013] f(x)=k1x 2 -k2x 3 ...Formula②;

[0014] Where x∈[0,1] represents the degree of change in the movement of the speed control element; f(x)∈[0,1] represents the proportional coefficient; K1x 2 Indicates the acceleration intensity of the initial section of the control curve, k2x 3 Generates the deceleration characteristics of the curve.

[0015] In this solution, the speed change of the lawn mower is achieved by an S-shaped smooth transition method based on a cubic polynomial, which can more effectively achieve a smooth change in the walking speed of the lawn mower and further ensure the stability of the lawn mower during the walking process.

[0016] Preferably, the moving range of the speed control member includes a forward zone, a backward zone, and a stop zone, and the operating component includes a position sensor for detecting an ADC value after the speed control member moves, and calculates the degree of change of the speed control member's movement based on the ADC value and the range value of the moving range in which the speed control member moves:

[0017]

[0018] In this solution, the original value of the moving range of the speed control member can be linearly mapped to the standardized interval [0, 1], thereby improving the calculation stability and ensuring the reliability of the calculation results.

[0019] Preferably, the forward and reverse zones include a buffer zone and a normal motion zone. When the speed control member moves through the buffer zone, the operating assembly controls the motor speed to zero. When the speed control member moves out of the buffer zone and into the normal motion zone, the operating assembly controls the motor speed to the target speed. The buffer zone in this solution can prevent the lawn mower from jerking when starting.

[0020] Preferably, the speed control member's range of movement includes an over-limit zone, and the operating assembly further includes a recognition module. Upon recognizing that the speed control member has exceeded the range of movement in the forward or reverse zone and entered the over-limit zone, the operating assembly controls the motor to rotate at a preset maximum forward speed or maximum reverse speed. This solution can prevent accidents caused by excessive speed of the lawn mower and ensure safe operation of the lawn mower.

[0021] Preferably, the operating component controls the change and update of the motor speed according to formula ④:

[0022]

[0023] where v next is the next speed value, v current is the current speed value; v target is the target speed value; Δ a ccel is the normal acceleration step length; Δ d ccel is the normal deceleration step size.

[0024] In this solution, when the lawn mower is operating normally, a gradual approach can be used to achieve steady speed updates, thereby ensuring stable operation of the lawn mower.

[0025] Preferably, the operating component controls the change and update of the motor speed according to formula ⑤ in an emergency state:

[0026]

[0027] where v next is the next speed value, v current The current speed value obtained by the motor’s real-time feedback; v target is the target speed value; Δ a ccel is the normal acceleration step length; Δ d ccel is the normal deceleration step length, η is the emergency braking coefficient, and min represents the f(min) function, that is, the minimum value is taken when the two are compared.

[0028] This solution can ensure the emergency braking capability of the lawn mower in an emergency state.

[0029] In a second aspect, the present invention provides a control method of the travel control system of the lawn mower of the present invention.

[0030] The present invention has the following beneficial effects:

[0031] 1. The present invention adopts a nonlinear speed regulation method to achieve a smooth transition of the lawn mower's walking speed, which can effectively ensure the stability of the lawn mower during walking, reduce the wear of the lawn mower parts, and increase the service life of the lawn mower.

[0032] 2. The present invention can provide emergency braking capability while ensuring the smooth operation of the lawn mower, thereby ensuring the safe operation of the lawn mower. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the speed control range of the speed control component in the embodiment of the travel control system and method of the lawn mower of the present invention. DETAILED DESCRIPTION

[0034] The following is further described in detail through specific implementation methods:

[0035] 1. Definition

[0036] Speed ​​control: A component on a lawn mower that allows the operator to control the speed of the mower. It can be a push rod or a pedal. Pressing the pedal forward moves the mower forward, and pressing it backward moves the mower backward. Pushing the push rod forward or backward moves the mower forward or backward.

[0037] 2. The embodiment is basically as follows: A travel control system of a lawn mower includes:

[0038] A traveling assembly, comprising a traveling wheel and a motor for driving the traveling wheel;

[0039] The operating assembly includes a speed control element, which controls the motor's rotation based on a speed signal provided by the speed control element. The speed control element's range of motion includes an overrun zone, a forward zone, a backward zone, and a stop zone. The forward and backward zones further include a buffer zone and a normal motion zone. The speed control element can be a pedal or a push rod. In this embodiment, a pedal is used as an example.

[0040] When the operating component obtains the degree of change in the movement of the speed control component, it uses a nonlinear speed regulation method to obtain the target speed corresponding to the motor, and the operating component controls the motor to rotate according to the target speed.

[0041] Specifically, when the operating component performs nonlinear speed regulation, the degree of change obtained is calculated according to formula ① to obtain the target speed corresponding to the motor.

[0042] targetSpeed=maxSpeed*f(x)……Formula ①;

[0043] Where targetSpeed ​​represents the target speed, maxSpeed ​​represents the preset maximum forward speed or maximum reverse speed; f(x) is calculated according to formula ②:

[0044] f(x)=k1x 2 -k2x 3 ...Formula ②;

[0045] Where x∈[0,1] represents the degree of change in the movement of the speed control component; f(x)∈[0,1] represents the proportional coefficient.

[0046] In formula ②, K1x 2 Indicates the acceleration intensity of the initial section of the control curve. The larger the value, the steeper the initial slope of the curve. The coefficient k1 = 3 ensures that the curve passes through the midpoint (f(x) = 0.5) at x = 0.5. If the coefficient K1 is less than 3, the curve will become flatter; if the coefficient K1 is greater than 3, the initial stage will be steeper. 2 ) makes the curve accelerate faster at the beginning. k2x 3 The deceleration characteristics of the curve are generated, and the ratio of its absolute value to the cubic coefficient determines the symmetry of the curve. When k2 is 2, it forms a 3:2 ratio with the quadratic coefficient, which can produce a perfect S-shaped symmetrical curve. 3 ) makes the curve slow down faster later in the curve, ensuring a smooth stop at x=1 (derivative is 0).

[0047] The operating component includes a position sensor that detects the ADC value after the speed control member moves, and calculates the degree of change in the speed control member's movement based on the ADC value and the range value of the movement range in which the speed control member moves:

[0048]

[0049] When the speed control member moves through the buffer zone, the operating component controls the motor's speed to zero. When the speed control member moves out of the buffer zone and into the normal movement zone, the operating component controls the motor to rotate at the target speed. When the speed control member exceeds the movement range of the forward or reverse zone and enters the over-limit zone, the operating component controls the motor to rotate at the preset maximum forward speed or maximum reverse speed.

[0050] While the lawn mower is moving, the operating component controls the motor speed according to formula 4:

[0051]

[0052] In formula ④, v nextis the next speed value, v current is the current speed value; v target is the target speed value; Δ a ccel is the normal acceleration step length; Δ d ccel is the normal deceleration step size.

[0053] In an emergency, the motor speed is updated according to formula ⑤:

[0054]

[0055] In formula ⑤, v next is the next speed value, v current The current speed value obtained by the motor’s real-time feedback; v target is the target speed value; Δ a ccel is the normal acceleration step length; Δ d ccel is the normal deceleration step length, η is the emergency braking coefficient, and min represents the f(min) function, that is, the minimum value is taken when the two are compared.

[0056] In the above formula, the acceleration step size, deceleration step size, etc. can be set independently as needed.

[0057] This embodiment also discloses a walking method using the above-mentioned walking control system of the lawn mower.

[0058] The specific implementation process is as follows: In this embodiment, the speed control member takes the pedal as an example, and the movement range of the speed control member is as follows: Figure 1 As shown, AB and HI are both over-limit areas. When the speed exceeds the forward interval or reverse interval, a warning will be issued and the vehicle will run at the maximum forward or reverse speed.

[0059] BD is the forward zone, and FH is the reverse zone. Within these zones, the mower moves forward or backward. CD and FG are buffer zones. When the pedal is pressed forward or backward from the stop zone, the mower first enters the buffer zone. Although the buffer zone is within the forward or reverse zone, the speed from the stop zone to the buffer zone remains zero until it leaves the buffer zone and enters the forward or reverse zone, where speed is generated, causing the mower to move forward or backward. When the pedal returns from the forward or reverse zone to the buffer zone, the speed at point C or point G is maintained within the buffer zone until the mower returns to the stop zone and stops.

[0060] EF is the stop zone. In this embodiment, the AD value of the entire motion range is 0-1024, with point E being the 0 point. The stop zone extends 50 AD values ​​to the left and right, and 100 AD values ​​to the left and right. Each time point E contacts the 0-position sensor after the pedal is released, the current AD value is automatically determined and set as point E (0 point). The various motion intervals are automatically calculated based on point E, and the size of the front and rear intervals can be adjusted based on actual conditions. Take the pedal E point value of 470 as an example: the stop zone is 420-520 values ​​(D: 420 value; F: 520 value, and so on. The forward zone is 520-950 values, and the reverse zone is 420-50 values. Set 950 as the maximum speed of 2800RPM. If it exceeds the value between 950-1024, it will exceed the limit and will be given 2800RPM. On the contrary, if it is lower than 50, it will be given according to the maximum reverse speed of 1500RPM at 50. The buffer zone of the forward zone is 520-560 values, and the reverse zone is 420-395 values.

[0061] When the mower is moving, the operator controls the speed of the mower by pressing the pedal forward or backward. During normal acceleration, the current speed v current is 500, and the acceleration step length Δ a When ccel is 400, the pedal is now depressed to the target speed v target When the speed is 2000, that is, the operator wants to set the speed of the mower to 2000, then according to the above formula, 2000-500=1500, and 1500>400, v next =500+400=900. When the current speed reaches 900, due to the target speed v target It is 2000, v current =900, then 2000-900=1100>400, v next =900+400=1300.

[0062] Similarly, we can calculate that the target speed v current =1300, v target =2000,2000-1300=700>400,v next =1300+400=1700.

[0063] Target speed v current =1700,v target =2000, 2000-1700=300<400, final v next =1700+300=2000, which means the target speed of 2000 is reached.

[0064] The above is only an embodiment of the present invention. Common knowledge such as the known specific structures and characteristics in the scheme is not described in detail here. Ordinary technicians in the field are aware of all common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all existing technologies in the field, and have the ability to apply conventional experimental means before that date. Ordinary technicians in the field can improve and implement this scheme in combination with their own abilities under the inspiration given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. The travel control system of the lawn mower includes: A traveling assembly, comprising a traveling wheel and a motor for driving the traveling wheel; An operating component includes a speed control component and controls the rotation of the motor according to a speed signal given by the speed control component; The feature is that when the operating component obtains the degree of change in the movement of the speed control component, it uses a nonlinear speed regulation method to obtain the target speed corresponding to the motor, and the operating component controls the motor to rotate according to the target speed.

2. The lawn mower travel control system according to claim 1, characterized in that: When the operating component performs nonlinear speed regulation, the degree of change obtained is calculated according to formula ① to obtain the target speed corresponding to the motor. targetSpeed=maxSpeed*f(x)……Formula ①; Where targetSpeed ​​represents the target speed, maxSpeed ​​represents the preset maximum forward speed or maximum reverse speed; f(x) is calculated according to formula ②: f(x)=k1x 2 -k2x 3 ...Formula②; Where x∈[0,1] represents the degree of change in the movement of the speed control element; f(x)∈[0,1] represents the proportional coefficient; K1x 2 Indicates the acceleration intensity of the initial section of the control curve, k2x 3 Generates the deceleration characteristics of the curve.

3. The travel control system of the lawn mower according to claim 2, characterized in that: The movement range of the speed control member includes a forward zone, a backward zone, and a stop zone. The operating component includes a position sensor for detecting an ADC value after the speed control member moves, and calculates the degree of change of the speed control member's movement based on the ADC value and the range value of the movement range in which the speed control member moves:

4. The travel control system of the lawn mower according to claim 3, characterized in that: The forward zone and the backward zone include a buffer zone and a normal movement zone. When the speed control member moves through the buffer zone, the operating component controls the speed of the motor to zero. When the speed control member moves out of the buffer zone and enters the normal movement zone, the operating component controls the motor to rotate according to the target speed.

5. The travel control system of the lawn mower according to claim 4, characterized in that: The moving range of the speed control member includes an over-limit zone, and the operating component also includes an identification module. When it is identified that the speed control member exceeds the moving range of the forward zone or the reverse zone and reaches the over-limit zone, the operating component controls the motor to rotate according to a preset maximum forward speed or maximum reverse speed.

6. The travel control system of a lawn mower according to any one of claims 1 to 5, characterized in that: The operating component controls the change and update of the motor speed according to formula ④: where v next is the next speed value, v current is the current speed value; v target is the target speed value; Δ a ccel is the normal acceleration step length; Δ d ccel is the normal deceleration step size.

7. The travel control system of the lawn mower according to claim 6, characterized in that: The operating component controls the change and update of the motor speed according to formula ⑤ in an emergency state: where v next is the next speed value, v current The current speed value obtained by the motor’s real-time feedback; v target is the target speed value; Δ a ccel is the normal acceleration step length; Δ d ccel is the normal deceleration step length, η is the emergency braking coefficient, and min represents the f(min) function, that is, the minimum value is taken when the two are compared.

8. A method for controlling the movement of a lawn mower, characterized in that: The travel control system of the lawn mower according to any one of claims 1 to 7 is used to control the travel of the lawn mower.

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