Forklift Distance Sensor Positioning Under Pallet Obstruction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Autonomous forklifts face challenges in detecting objects in front of the fork due to the pallet obstructing the laser sensor's scanning path when holding a load.
Innovation Solution
A forklift design with a distance sensor movable relative to the fork, a restriction mechanism to prevent downward movement, and a guide mechanism to switch between storage and measurement positions, allowing the sensor to operate effectively even when holding a pallet.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the laser sensor is fixed to the fork for detecting pallet position, then the structure is simple, but the sensor cannot detect objects in front when holding a pallet due to obstruction
Solution Approach 1:
The distance sensor is made movable relative to the fork through a guide mechanism, allowing it to switch between a storage position (when not holding pallet) and a measurement position (when holding pallet). This dynamic repositioning enables the sensor to avoid obstruction by the pallet while maintaining detection capability.
2Reliability
If the distance sensor is positioned low for measurement, then it can detect objects in front when holding pallet, but it may be damaged when the fork is low on the floor
Solution Approach 1:
The distance sensor's position is dynamically adjusted based on fork height. When the fork is low on the floor, the sensor is positioned high at the storage position, avoiding damage from contact with the floor or obstacles. When the fork is raised to hold a pallet, the sensor moves to the lower measurement position to detect objects in front.
Solution Approach 2:
The sensor is pre-positioned at the storage position before the fork makes contact with the floor or obstacles, preventing damage in advance. The restriction mechanism ensures the sensor cannot move below a safe position when the fork is low.
3Reliability
If the distance sensor moves with the fork throughout, then it maintains relative position, but it cannot detect objects in front when the pallet blocks the view
Solution Approach 1:
The distance sensor is decoupled from the fork's vertical movement through a guide mechanism that allows independent positioning. The sensor can maintain a fixed measurement position relative to the pallet while the fork moves vertically, enabling detection of objects in front even when the pallet is held at various heights.
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 accurate detection of objects in front of the forklift while carrying a load, preventing sensor obstruction and damage, and achieving reliable autonomous navigation without additional power sources or controls.
Implementation Method 1
a laser sensor is used for detecting a position of a fork insertion opening of a pallet. The laser sensor detects a shape of the pallet by performing scanning over a predetermined range on a front side in a horizontal direction with a laser beam.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A forklift capable of recognizing a state on a front side even when holding a pallet is provided. A forklift includes: a fork movable in a height direction; a distance sensor held by the fork to be relatively movable with respect to the fork in the height direction, the distance sensor measuring a distance to an object existing in a forward direction; and a restriction mechanism restricting a movement of the distance sensor in a downward direction of the height direction when the fork is placed within a first height range from a floor surface to a first height. The distance sensor is: placed at a storage position spaced from the floor surface when restricted by the restriction mechanism; and placed at a measurement position lower than a lower surface of a pallet held by the fork when the fork is placed within a second height range equal to or higher than the first height.