Cart Handle Assembly Force Sensing and Power Assist
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Solution Overview
Problem
Carts require significant user force to move when loaded, and existing force-sensing systems are complicated and prone to vertical vibrations, making accurate force direction sensing challenging.
Innovation Solution
A handle assembly with a force sensing module that includes a moving frame, spring, permanent magnet, Hall sensor, and sensor PCB, which senses the direction of force applied and provides power assistance by transmitting this information to a controller to assist the user, while minimizing vertical vibrations through a secure structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a cart is loaded with increased number of objects or heavy object, then the cart can carry more load, but a user is required to apply large force to move the cart
Solution Approach 1:
The patent replaces the purely mechanical pushing system with an electromechanical system. A force sensor detects the user's pushing force, and a motor provides auxiliary propulsion force based on the detected signal, thereby reducing the effort the user must exert while maintaining the ability to carry heavy loads
2Measurement precision
If a sensor is provided to sense the direction of force applied for movement of the cart, then force direction can be detected, but vibration occurs not only in the horizontal direction but also in the vertical direction due to movement of the cart on the ground, thereby complicating control for accurate sensing
Solution Approach 1:
The patent segments the force sensing function into two independent components: a horizontal force sensor that detects only the horizontal pushing force component, and a motor control system that acts based on this signal. This segmentation allows the system to ignore vertical vibrations and other interfering signals, simplifying the control logic while maintaining accurate force direction detection
Solution Approach 2:
The patent introduces an intermediary horizontal force sensor that selectively detects only the horizontal component of the applied force. This intermediary device filters out vertical vibrations and other interfering signals before they reach the control system, thereby simplifying the control algorithm while maintaining accurate force direction sensing
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
Enables convenient and accurate movement of carts by providing power assistance in the direction of force applied, improving user convenience and control efficiency while reducing manufacturing costs by simplifying control algorithms.
Implementation Method 1
a Hall sensor disposed adjacent to the magnet and sensing a location of the magnet
Implementation Method 2
a spring coupled at one end thereof to an interior of the handle bar and having the other end extending to be adjacent to the moving frame, the spring being pressed and deformed by the moving frame in a direction of the external force applied to the cart
Data Source
AI summary
A handle assembly for a cart with a power assist function can sense the direction that a user's force is applied, and provide assist power in the corresponding direction, such that the user can easily move the cart. A cart including the handle assembly allows the user to conveniently move the cart.