Self-Propelled Mower Handle Thrust Sensing Speed Control
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Solution Overview
Problem
Existing rear-moving self-propelled lawn mowers require manual control, resulting in reduced user comfort due to constant speed limitations, where moving slower than the mower feels pulling and moving faster feels hindering, leading to increased labor intensity and reduced mowing efficiency.
Innovation Solution
A rear-moving self-propelled working machine with a handle device equipped with a pressure sensor and trigger assembly that adapts the mower's speed to the user's thrust, allowing for smooth speed adjustment and improved comfort by sensing the applied force and controlling the motor's output torque accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the lawn mower operates at constant speed, then the motor control is simple, but the user comfort deteriorates due to pulling or hindering sensations
Solution Approach 1:
The patent implements feedback control by using a pressure sensor to detect the thrust applied by the user on the handle device, then transmitting this signal to the controller which adjusts the motor's output torque accordingly. This closed-loop feedback system allows the mower to automatically adapt its speed to match user intent, eliminating the pulling or hindering sensations experienced with constant speed operation.
Solution Approach 2:
The patent transitions from static constant speed control to dynamic speed adjustment. The motor speed is no longer fixed but dynamically changes in real-time based on the detected user thrust. This dynamic control allows the mower to accelerate or decelerate smoothly according to user input, significantly improving operational comfort.
2Device complexity
If manual control is used, then the device structure is simple, but the labor intensity increases
Solution Approach 1:
The patent enables the lawn mower to perform self-service by automatically adjusting its own speed based on user input. The pressure sensor detects user thrust, and the controller autonomously regulates motor torque and speed, eliminating the need for manual throttle control. This self-adjusting capability reduces user effort while maintaining simple overall device structure.
Solution Approach 2:
The patent replaces manual mechanical throttle control with an automated sensing and control system. The pressure sensor and electronic controller substitute for traditional mechanical speed control mechanisms, detecting user intent and translating it into appropriate motor torque adjustments, thereby reducing physical effort required.
3Measurement precision
If the pressure sensor is directly connected to the operation member, then the detection accuracy is high, but the signal transmission distance causes interference
Solution Approach 1:
The patent introduces an intermediary signal transmission path where the pressure sensor is mounted on the connecting rod assembly rather than directly on the operation member. This intermediate positioning allows the sensor to detect thrust forces transmitted through the mechanical linkage while being positioned closer to the controller, reducing signal transmission distance and minimizing interference. The connecting rod assembly acts as a mechanical intermediary that transmits force information reliably.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enhances user comfort by ensuring the mower's speed aligns with the user's pace, reducing physical effort and maintaining consistent control, thus improving the overall mowing experience.
Implementation Method 1
the trigger assembly applies the force to the pressure sensor to drive the pressure sensor to deform
Data Source
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AI summary
Provided is a rear-moving self-propelled working machine. The rear-moving self-propelled working machine includes a main machine and a handle device. The main machine includes a moving assembly and a motor for driving the moving assembly. The handle device is connected to the main machine and includes an operation member, a connecting rod assembly, a housing, a sensing device, and a trigger assembly. The operation member includes a grip for a user to hold. The connecting rod assembly includes a first connecting rod connected to the main machine. The housing is formed with a first accommodation cavity, where the first connecting rod extends into the first accommodation cavity. The sensing device is used for sensing a thrust applied to the handle device to drive the rear-moving self-propelled working machine. The trigger assembly is capable of applying a force to the sensing device when the grip receives the thrust. The trigger assembly is connected to the connecting rod assembly, and the sensing device is connected to the operation member.