Semiconductor Light Array Weeding With Safer Focused Irradiation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser-based weeding systems pose safety risks due to high-power collimated beams, are costly, unreliable, and complex, with moving parts prone to failure, and have a significant environmental impact.
Innovation Solution
A weeding apparatus using a two-dimensional array of low-power semiconductor emitters, enclosed within a water-tight enclosure, delivers concentrated light safely by shaping ground reflections as diffusing cones, reducing complexity and cost, and incorporating autonomous or manual operation with robotic aiming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single high-power collimated laser beam is used for weeding, then the weed control effectiveness is improved, but the safety risk increases due to ground reflections reaching human eyes
Solution Approach 1:
The single high-power collimated beam is segmented into multiple lower-power beams arranged in a two-dimensional array. This segmentation maintains the total energy required for effective weed control while distributing the energy in a pattern that prevents dangerous concentrated reflections from reaching human eyes, thus resolving the contradiction between effectiveness and safety
Solution Approach 2:
The invention transitions from a one-dimensional single beam to a two-dimensional array of beams. This dimensional change allows the energy to be distributed across multiple spatial coordinates, maintaining total power for effectiveness while the geometric arrangement ensures reflections diverge safely, resolving the safety-effectiveness contradiction
2Productivity
If a single high-power collimated laser beam is used for weeding, then the weed control effectiveness is improved, but the system cost and complexity increase due to complex light coupling and active water cooling requirements
Solution Approach 1:
The system segments the single high-power beam requirement into multiple lower-power semiconductor laser sources. Each source operates at a manageable power level that eliminates the need for complex active water cooling systems and sophisticated light coupling mechanisms, thereby reducing overall system complexity while maintaining weed control effectiveness through the combined array
Solution Approach 2:
The invention employs multiple inexpensive semiconductor laser sources that can be readily replaced if needed, rather than relying on a single expensive, complex, and fragile high-power laser system. This approach reduces both initial cost and long-term maintenance complexity
3Productivity
If a single high-power collimated laser beam is used for weeding, then the weed control effectiveness is improved, but the reliability decreases due to moving mirror systems being prone to failure
Solution Approach 1:
The system segments the beam delivery into multiple fixed semiconductor laser sources arranged in a two-dimensional array, eliminating the need for moving mirrors and galvanometers. This segmentation into static, simple components dramatically improves reliability while maintaining the concentrated energy delivery needed for effective weed control
Solution Approach 2:
The invention extracts and removes the unreliable moving mirror system and galvanometer components from the design. By using a fixed two-dimensional array of semiconductor lasers, the system eliminates mechanical moving parts that are prone to failure, thereby improving reliability without sacrificing weed control effectiveness
4Productivity
If a single high-power collimated laser beam is used for weeding, then the weed control effectiveness is improved, but the operational cost increases due to expensive and fragile lasing systems
Solution Approach 1:
The system segments the expensive single high-power laser into multiple inexpensive semiconductor laser sources. The total cost of many low-power, commercially available semiconductor lasers is significantly lower than a single high-power system, while the array configuration maintains the energy concentration needed for effective weed control, thereby reducing operational cost
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 system enhances safety, reliability, longevity, and reduces operational costs while providing efficient weed control with minimal soil disturbance and environmental footprint.
Implementation Method 1
multiple semiconductor emitters, such as laser diodes or LEDs (light emitting diodes)
Implementation Method 2
Transverse single-mode laser diodes are not appropriate due to their emitting spatial distribution
Implementation Method 3
The proposed solution is based on the convergent concentration of light from many cheap and reliable semiconductor emitters in a two-dimensional array within a weeding concentrator assembly
Implementation Method 4
any ground reflection of the concentrated beam would be shaped as a diffusing and diverging cone of light with homogeneous irradiance on any crossing plane
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Weeding apparatus includes a concentrator assembly having a two-dimensional array of discrete semiconductor light emitters (2), e.g. laser diodes or LEDs. A primary optical stage (3) includes collimating lenses (4) each corresponding to one of the semiconductor light emitters (2) to collimate their light and produce a compound collimated beam. A secondary optical stage (5) incorporates a lens system arranged to convert the collimated beam into a convergent beam to concentrate the emitted light at a focal position. The concentrator assembly (1) may be incorporated in a weeding unit with a mechanical drive arrangement to direct the focal position onto a selected plant. A number of such weeding units maybe incorporated in a weeding module along with a control system. The weeding modules can be carried by an autonomous rover.