Ultrasonic Object Detection Sensors Reduce Costs on the Farm

Application Note

Senix: The innovative Sonic Spray attachment from farm equipment manufacturer Gillison’s Variety Fabrication, Inc. (GVF) uses Senix ultrasonic object detection sensors to detect orchard trees and precisely control the application of sprayed materials.

Sonic Spray growers use 25% to 40% less spray material.

The GVF Sonic Spray saves farmers money by reducing the amount of spray material used, simply by turning off the spray when no tree is present. Sonic Spray reduces material usage by 25% to 40%, depending on tree size and row spacing. It also reduces unproductive trips back and forth to refill the sprayer. Matt Gillison, developer of the Sonic Spray, said, “Even small growers realize a return on investment in less than two years. There are very few agricultural investments that offer that kind of ROI and an environmental benefit as well.”

Ultrasonic Object Detection Sensors

The Sonic Spray uses six high-speed ToughSonic 50 ultrasonic sensors to detect trees. The spray valves are turned on or off at exactly the right time to treat the trees, but not the empty space between the trees.

When a tree is detected by one or more sensors, a signal is sent to the system controller. The sensor’s analog output is combined with data on ground speed and operator inputs to control spray valves. This output is also displayed on the CAN display so the operator can see what each sensor is detecting.

The operator has push-button control over which sensor and spray zones are active and the maximum distance each sensor will measure. For example, if the display indicates that the sensors are picking up trees from the next row, the maximum detection distance can be reduced so the further trees are ignored.

GVF Chose Senix Ultrasonic Sensors

GVF partnered with their distributor, J H Bennett, to select the right ultrasonic sensor technology for this unique application. Senix ToughSonic sensors were run through a battery of tests alongside several competing brands.

Easy sensor configuration

GVF used SenixVIEW configuration and analysis software, to adjust ultrasonic sensors during product development and testing . “Being able to connect a laptop and fine tune system performance in the field definitely accelerated our product development process,” said Matt Gillison. Similarly, the ability to provide Sonic Spray operators with real-time, push-button command over sensor behavior significantly improves control and productivity.

Sensor networking and synchronization

Synchronizing all six sensors to prevent them from receiving signals from one another was also important. Using the ToughSonic SYNCH feature and RS-485 serial output offered on all Senix sensors, GVF was able to tune the on-board sensor array. Master and slave sensors are defined and each one operates in precise synchronization with the others. A 50 millisecond measurement interval is maintained to detect small branches even while traveling at 3 mph to 4 mph.

Simultaneous sensor outputs

GVF needed an ultrasonic sensor that could provide simultaneous serial and digital outputs. The speed of RS-485 communications was necessary to synchronize all six sensors, while the analog output provides system control and operator display data. Senix ultrasonic sensors are unique in their ability to provide multiple simultaneous serial, analog and switch outputs.

Customer service

Senix engineers worked with GVF and J H Bennett before and after the sale to get the system running. “We worked well with Senix to get this product up and running. [Ultrasonic sensor] durability has been good and the Sonic Spray has been performing very well in the field,” said Matt Gillison.

Farm-tough ultrasonic sensors

And finally, any sensor installed on farm machinery has to be weather-tight, rugged and durable enough to withstand regular use in the field.