Zero-Turn Mower Blade Control via Unified Motor Coordination
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Solution Overview
Problem
Existing ZTR mowers with electric powertrains face challenges in synchronizing the rotational speed and direction of multiple electric motors for the wheels and blades, requiring complex control systems that lack coordinated operation.
Innovation Solution
A single master controller is used to coordinate the rotational speed and direction of both the wheel and blade motors, receiving inputs from user controls and position sensors to enhance operational efficiency and battery life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multiple separate controllers are used for each electric motor, then each motor can be controlled independently, but the control system complexity increases and coordinated operation becomes difficult
Solution Approach 1:
The patent combines multiple separate motor controllers into a single integrated controller that manages all electric motors (wheel motors and blade motors). This unified controller receives steering inputs and automatically distributes appropriate control signals to each motor, maintaining independent control capability while eliminating the complexity of multiple separate control systems.
2Reliability
If a complex control system is used to synchronize multiple electric motors, then coordinated operation can be achieved, but the system becomes more complex and harder to control
Solution Approach 1:
The integrated controller automatically determines the appropriate rotational speed and direction for each motor based on the steering input received from the operator. The controller self-regulates the coordination between wheel motors and blade motors without requiring complex external control systems, achieving reliable synchronization through autonomous decision-making embedded in the single controller.
3Reliability
If continuous voltage is supplied to blade motors, then blade rotation is maintained, but power consumption increases and battery life decreases
Solution Approach 1:
The controller implements periodic voltage pulsing to the blade motors instead of continuous voltage supply. By delivering intermittent voltage pulses that maintain blade rotation through momentum, the system reduces overall power consumption from the battery while preserving continuous cutting operation. This pulsed operation mode extends battery life during mowing tasks.
4Productivity
If blade speed is not optimized based on wheel speed, then blade motors operate at constant speed, but energy efficiency decreases during turning maneuvers
Solution Approach 1:
The integrated controller dynamically adjusts the rotational speed of blade motors based on the real-time operating conditions, particularly the speed and direction of the wheel motors. During turning maneuvers or changes in mowing speed, the controller automatically modulates blade motor speeds to match the actual mowing requirements, optimizing energy efficiency while maintaining effective cutting performance.
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 master controller enables precise coordination of motor operations, optimizing blade speed based on wheel speed, reducing power consumption, and extending battery life by pulsing voltage to motors, and adapting to turning maneuvers.
Implementation Method 1
The master controller is configured to send voltage pulses to the multiple blade motors
Data Source
AI summary
A ZTR mower includes a pair of rear drive wheels, a mowing deck including multiple cutting blades, an electric storage battery, a pair of electric wheel motors each configured to rotate one of the rear drive wheels, multiple electric blade motors each configured to rotate one of the multiple cutting blades, and a master controller in communication with each of the pair of wheel motors and the multiple blade motors. The master controller is configured to control a rotational speed of each of the pair of wheel motors and the multiple blade motors. The master controller is configured to send voltage pulses to the multiple blade motors.