Background
The BenchBot Image Acquisition System and likely PlantMap3D applications, have the need for a relatively low cost (for PM3D at least) and waterproof (for both) camera flash system.
We have not been able to find a suitable COTS device. Existing industrial flashes are both too expensive $1500+ per unit, and not bright enough (RHI200-DO lighting for logistics - Smart Vision Lights).
The existing consumer grade flash we use (Godox Witstro Ring Flash AR400 AR400 B&H Photo Video (bhphotovideo.com) Is typically bright enough for Ag Image Repo applications, although in certain circumstances, such as very harsh daylight shadows, there could be a benefit to having a more intense flash. Although it is more than bright enough for PM3D applications, which have less intense image quality requirements. However, this type of flash is not suitable for long term usage in our application. First, there is no ingress protection. Second, it is hard to integrate both mechanically and electrically into a robotic system. And third, while a reasonable cost ($450) for BB/IAS application, it would not be affordable for PM3D MultiOak / cam where 4-8 units would be needed for each system.
To Summarize:
Existing Consumer Flash Units
Awkward to mechanically integrate
Awkward to electrically integrate
No meaningful ingress protection
low durability / reliability
Still too costly for the multi camera systems
Existing Industrial Flash Units
Expensive ($1500+) per unit
Not bright enough for BB / IAS applications
Very few options / suppliers available
Limits install flexibility
For these reasons we are exploring the design of an in-house flash unit to fulfill our needs.
Direction
The flash system will likely be LED for the following reasons:
LEDs are more physically durable than Xenon flash tubes.
A well implemented LED flash should lasty much longer than Xenon tubes.
LED flash systems require much lower voltages (50-100V vs. 300-500V) which helps size, cost, complexity, and safety.
Building a flash from multiple LED modules provides more flexibility than Xenon tubes which come in a limited number of sizes and shapes.
An LED flash can be controlled in a much more precise way than Xenon tubes, where if implemented both brightness and duration can be precisely controlled.
Initial research has found that there is a significant lack of information / standard designs with LED camera flashes. So, the design phase will be proceeded by a more significant research / prototyping stage than our typical hardware projects.
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