Water Truck Arm
Presenters: Maggie Barnes, Elyssa Roberts, TJ Wink
Faculty Mentor: Mick Peterson
University of Kentucky Biosystems and Agricultural Engineering
PROBLEM STATEMENT AND OBJECTIVE
Horse track consistency reduces the need for horses to adapt to surface changes and reduces likelihood of slipping. A primary cause of inconsistency is moisture content across the track. One method of controlling water content uses a truck with an arm as shown in Figure 1. As the water truck moves along the track, sprayers distribute the water at a constant rate. During a turn, the arm at the inside of the track moves slower than the outside, causing inconsistent surface moisture around curves.
The objective of the project is to create a water truck arm capable of distributing moisture evenly around the racetrack, whether it is going around a curve or a straight away.
Figure 1: A water truck used at Keeneland, a thoroughbred horse racing facility in Lexington, KY
Figure 2: AutoCAD rendering of proposed design
Figure 4: Schematic of proposed design for electronic controls system
BACKGROUND
- Consistency and evenness of the moisture content of horse racing tracks is a key element in the soil's physical attributes such as shear strength, deceleration capabilities, and energy return
- Safety is one of the largest contributors to establishing the sports ethicality
- To distribute water onto the racetrack, facilities often use water trucks that use a large tank and an arm equipped with nozzles and sprayers
- When the truck drives around the corners of the racetrack, the outer side of the arm may move 2-3 times faster than the inside
- The nozzles that control the flow from the arm can vary based on size, height from ground, spray pattern, and overlap
- The Horseracing Integrity and Safety Authority (HISA) enforces the racetrack surface monitoring and maintenance by establishing practices for testing, design, and record keeping
- Based on typical water truck usage and data, the flow rate required was determined to be 4000 gallons in 7 minutes on a 1 1/16th mile long track
- Certain current agricultural pesticide boom applicators are capable of turn compensation, but these systems can cost between tens and hundreds of thousands of dollars and have much lower flow rates
- All the background information went into determining considerations, criteria and constraints as shown in Table 1
PROPOSED SOLUTION
- The proposed solution is made up of an arm, electrical solenoid valves, nozzles, and control system as shown in Figure 2
- The proposed solution is shorter than an actual arm for demonstration purposes
- The arm’s body is made from a 3-inch aluminum pipe attached to a pump with a hose and globe valve to turn the system on and off
- Based on P&ID diagrams pump size was established to be a 4-inch centrifugal pump rated at 648 gallons per minute
- The arm spans 6 feet in length, and is equipped with 5 nozzles, each spaced 1 foot apart
- At each nozzle, a solenoid valve controls the flow that is distributed onto the track
- The nozzles are rated for up to 23.7 gallons a minute at 100 psi
- Using five nozzles, the required flow per nozzle is around 19 gallons a minute
- Spacing decided based on 100% overlap conditions to promote higher consistency and even moisture content across track
ACKNOWLEDGEMENTS AND REFERENCES
Acknowledgements: Water Truck Arm Team, Walker Precision, Mick Peterson, Joel Bradley, Sydney Cannon, Alfredo Laureano, Tim Stombaugh, Joe Dvorak
References:
Azimi, A. H., Carpenter, T. G., & Reichard, D. L. (1985). Nozzle Spray Distribution for Pesticide Application. Retrieved from elibrary.asabe.org: https://elibrary.asabe.org/abstract.asp?aid=32451
PROCESS FLOW OF PROPOSED DESIGN
- The physical configuration of the arm differs very little from other water truck arms
- The difference in the proposed solution lies in the controls
- The solenoid valves can partially close and open, and if each valve is operated individually, flow can be modified to spray differently when the truck rounds a curve
- At the curve, the arm at the inside of the track moves slower than the outside, which results in more moisture at the inner radius of the racetrack
- The valves closer to the inner radius of the track can be closed more than the valves at the outside.
- The process flow is depicted in Figure 3
PLAN FOR SPRING SEMESTER 2024
- Complete design documentation at the end of the Fall 2023 semester
- Constructing and assembling the valve and nozzle system by welding, wiring, and plumbing components together
- Hanging the arm to the yellow steel rotating beam provided in Lab 151
- Buy and test solenoid valve to see if the valve is controllable at high flow rates
- Test sprayer distribution and PWM to ensure correct flow rate
- Test moisture distribution while moving the arm
Figure 3: Process flow diagram of proposed design
Table 1: Design considerations, criteria, and constraints
- The wiring for the electronic controls system is shown in Figure 4
- To actuate the closing and opening of the valves, an Arduino can be used to control the voltage sent from an external power supply that feeds into the valves
- By quickly turning off and on the signal sent from the power supply the valves can be controlled using pulse width modulation (PWM)
- Since the Arduino is not directly sending the signal that powers the valves, a PWM driver board is used
- The driver board can separately control multiple channels from a signal sent from the Arduino and send the external signal out appropriately
- A GPS module is used to determine when the truck is driving around in turn
- Based on input of current location from the GPS and the predetermined coordinates of the turns, the system can decide if a turn is occurring
- Pressure transducers can be used to monitor the pressure losses from each nozzle to ensure that the correct pressure is being supplied at every location
- In addition, a flow meter can be used to monitor flow through the arm