Omnidirectional Cart Velocity Limiting for Excessive User Input
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Solution Overview
Problem
Existing carts fail to effectively limit velocity in response to excessive user operations, leading to unintended acceleration during turning or straight-line movement.
Innovation Solution
A cart equipped with omnidirectional wheels, a handle, a load sensor, and a control unit that adjusts velocity limits based on detected loads and moments, using correction coefficients to restrict excessive operations while maintaining intended direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cart executes deceleration control during turning, then unintended acceleration due to erroneous operation is suppressed, but velocity is not limited when the cart goes straight or translates even with excessive operation input
Solution Approach 1:
The control unit dynamically adjusts the gain parameter based on the cart's movement state (turning vs. straight/ translating). When turning is detected, a first gain is applied for deceleration control; when moving straight or translating, a second gain is applied to limit velocity. This parameter change resolves the contradiction by adapting the control response to the specific movement context.
2Productivity
If the cart allows high velocity in response to user operation, then productivity and responsiveness are improved, but safety and control are compromised due to unintended acceleration
Solution Approach 1:
The control system dynamically adjusts velocity limits and gain parameters based on real-time detection of movement state and operation magnitude. The system transitions between different control modes (turning mode with deceleration control, straight/ translating mode with velocity limitation) to balance productivity and safety according to current operational conditions.
Solution Approach 2:
The control unit continuously monitors operation input magnitude and cart movement state, using this feedback to adjust control parameters. When excessive operation is detected during straight or translating movement, the system applies velocity limitation feedback control to prevent unintended acceleration while maintaining responsiveness to valid user input.
Data Source
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AI summary
A cart includes a control unit configured to multiply a provisional target front and rear velocity by a correction coefficient thereby setting a target front and rear velocity and multiply a provisional target lateral velocity by the correction coefficient thereby setting a target lateral velocity if the provisional target front and rear velocity is equal to or higher than a front and rear velocity upper limit or if the provisional target lateral velocity is equal to or higher than a lateral velocity upper limit, set the provisional target front and rear velocity to the target front and rear velocity and set the provisional target lateral velocity to the target lateral velocity if the provisional target front and rear velocity is lower than the front and rear velocity upper limit and the provisional target lateral velocity is lower than the lateral velocity upper limit.