Forklift Travel Control Using Steering-Angle-Based Speed Limits
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Solution Overview
Problem
Existing material handling vehicles lack effective systems to control travel based on intrinsic aspects of the vehicle and its environment, leading to potential collisions due to undetected obstacles during steering maneuvers.
Innovation Solution
A travel control system that integrates with an object detection system, using sensors to determine speed limits based on steering angles and vehicle properties, adjusting speed to prevent collisions by ensuring the stopping distance remains within the scanner's field of view.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the material handling vehicle travels at high speed during steering maneuvers, then productivity is improved, but the risk of collision increases due to insufficient stopping distance when obstacles are outside the scanner field of view
Solution Approach 1:
The system performs preliminary detection of obstacles outside the current scanner field of view by calculating potential obstacle positions based on steering angle and vehicle dynamics. Before the obstacle enters the field of view, the system pre-calculates the required stopping distance and adjusts speed accordingly to ensure the vehicle can stop safely within the scanner's detection range.
Solution Approach 2:
The system dynamically adjusts the speed limit based on real-time steering angle, vehicle speed, and calculated stopping distance. As the steering angle changes, the system continuously updates the maximum allowable speed to maintain the relationship where stopping distance remains within the scanner field of view, enabling adaptive speed control that balances safety and productivity.
2Reliability
If the scanner field of view is widened to detect more obstacles, then safety is improved, but the device complexity increases
Solution Approach 1:
Instead of expanding the scanner's physical field of view in angular dimensions, the system extends detection capability in the temporal and computational dimensions. By calculating where obstacles will be based on current steering angle and vehicle dynamics, the system effectively detects obstacles outside the current field of view without adding physical sensors or widening the scanner's angular coverage.
Solution Approach 2:
The system introduces computational modeling as an intermediary between the scanner and obstacles. Rather than directly detecting all obstacles with expanded hardware, the system uses vehicle dynamics models and steering angle data as intermediaries to predict obstacle positions, thereby extending detection capability without physical expansion of the scanner field of view.
3Reliability
If the system continuously monitors and adjusts speed based on steering angle and stopping distance, then safety is improved, but the device complexity increases due to additional sensors and control mechanisms
Solution Approach 1:
The system makes the existing scanner serve multiple functions: not only detecting obstacles within its current field of view but also indirectly detecting obstacles outside the field of view through computational analysis of steering angle and vehicle dynamics. This multi-functionality eliminates the need for additional dedicated sensors while maintaining enhanced safety capabilities.
Solution Approach 2:
The system uses the vehicle's own operational data (steering angle, speed, vehicle dynamics) to perform obstacle detection and speed control. Rather than requiring separate dedicated sensors and control systems, the system leverages existing vehicle operational parameters to self-regulate speed and maintain safety, reducing the need for additional complex components.
Data Source
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AI summary
Systems and methods provide a travel control system to augment a supplemental object detection system of a material handling vehicle. Speed limits can be calculated for material handling vehicles based on properties of the vehicle, and a field of view of the object detection systems of the material handling vehicle. For given steer angles or ranges of steer angles, the speed of the material handling vehicle can be limited to ensure that the vehicle could stop before contact with a newly-detected object that was previously outside the field of view of the object detection system.