Pied Piper
Project Leads: Elijah Shumway [email protected] Vincent Vaughn-Uding [email protected]
The Pied Piper device is a vibrational camera trap for autonomously monitoring the activity patterns of North American Alfalfa Treehoppers, which are agricultural pests. These Treehoppers are able to spread Red Blotch Disease, which is a virus that infects grapevines and can reduce both the yields and quality of the grapes they produce. Information on the activity patterns of Treehoppers is valuable, because it can be used for developing and testing methods of controlling their populations, and for better understanding the effects that they have on their host plants.
The device is used to measure the spatial and temporal distribution of treehopper activity. It works by detecting the vibrational mating calls of male treehoppers using a contact microphone (and associated electronics, signal processing, and detection algorithm), and then playing back an artificial female mating call using a vibration exciter to lure them closer to the trap, where they can then be imaged using an onboard camera. The device records the exact time and audio responsible for each positive detection, which allows it to produce much higher-resolution temporal data on the times of maximum insect activity versus a traditional mechanical or adhesive trap.
State machine diagram of the Pied Piper mating call detection algorithm
Construct a device that:
- Effectively recognize when an insect is present
- Successfully attract insects towards the trap
- Can determine the times of highest activity of these insects
| Specification | Range |
|---|---|
| Insect detection accuracy at 1m along substrate | 90% |
| Insect attraction success rate* | 90% |
| Mating call playback amplitude | 1mm/s at 1m |
| Battery Life | 3 Months |
| Cost | <$250 |
| Weatherproofing | IP66 |
| Specification | Range |
|---|---|
| Insect detection accuracy at 1m along substrate | 90% |
| Insect attraction success rate* | 90% |
| Mating call playback amplitude | 1mm/s at 1m |
| Battery Life | 1 Month |
| Cost | $238 |
| Weatherproofing | IP67 |
*This is defined as the chance that a detected Treehopper is lured towards the trap and enters the range that it can be identified by the camera.
The device uses a custom PCB to integrate all of its electronic components. Except for the microphone preamplifier, all of the major electronic components of the system are discrete modules that are attached to the PCB using connectors that can be easily removed without soldering.
Preview Image of the Pied Piper PCB
The device uses a piezoelectric contact microphone to sense substrate-borne vibrations, and a conditioning preamplifier is used to amplify the voltage output by this microphone is amplified to levels that can be measured by the microcontroller's onboard ADC. The preamplifier is also used to provide compression to the audio signal, which maximizes its dynamic range.
A vibration exciter driven by a sound board is used to play artificial mating calls to lure treehoppers closer to the trap. The sound board communicates with the microcontroller through a TTL serial interface, and it contains all of the recorded mating call audio on its own internal storage; the microcontroller does not send any audio data over the serial link, it only tells the sound board which sound to play.
A camera module is used to image insects on the substrate, and it is accompanied by an array of LEDs that provide illumination. The camera has onboard storage for the image data it collects, and it is controlled through a single-wire interface with the microcontroller.
The Pied Piper is currently able to distinctly recognize a specific insect's mating call from other variations of insect mating calls. The system is 86.67% accurate at recognizing an insect's mating call at distances of 25 cm away from the source. Upon recognition, the system plays back the resulting insect call through a vibration motor into the substrate.
As development continues on, the sensitivity and accuracy of the PiedPiper will be improved upon to reach a 90% detection rate at distances of up to one meter. The overall power consumption of the board will also be improved to lengthen the battery life in the field. The Pied Piper has entered its testing phase and two prototypes are currently being tested in field to determine its effectiveness at recognizing and attracting insects. A new version of the Pied Piper is also being worked on and will include i2c potentiometers and an improved board design.
- R. W. Mankin, D. K. Weaver, M. Grieshop, B. Larson, and W. L. Morrill, “Acoustic System for Insect Detection in Plant Stems: Comparisons of Cephus cinctus in Wheat and Metamasius callizona in Bromeliads1,2,” vol. 21, no. 4, p. 11, 2004.