Electric Liquid Level Sensing System

1. Electric Liquid Level Sensing System Team 8 Abstract: The Wayside Top of Rail system disburses a lubricant, which reduces the curving forces, rail wear, and energy needed to propel trains. Internal pumps are self-lubricated and can fail if the lubricant falls below the intake. The designed solution is a series of multiple sensors retrofitted on a current system to monitor the lubricant level inside the tank. This robust system includes sensors for temperature, audio frequency, and Radio Frequency Identification (RFID). This fail-safe integrated implementation is designed to shut off the pumps at a critical level to prevent damage to the pumps. The sensing system will also provide the status of the tank locally within the electronics cabinet. Design Requirements: Norfolk Southern has requested a liquid level sensing system to be an effortlessly implementable system onto tanks that are currently in place. The challenge was to put this system into operation without modifying the tank in any way. Any modification, such as drilling into the tank, will be impractical while it is operational and filled to capacity. In addition, debris could enter the pumps causing damage. The internal level sensing system also needs to be implemented with caution. The lubricant has a tendency to bond on other objects and solidify when exposed to air for an extended period. The other objective is to utilize a small amount of power since the whole system, including the new liquid level sensing system, runs off a car sized battery that is charged by a solar panel. End-Product Description: The final design that has been developed consists of three types of sensors. The first sensor is an audio frequency sensor. This sensor consists of a solenoid that strikes the side of the tank and a microphone that picks up the audio vibration. The audio data is then processed to find if the lubricant level is at the critical point. The next sensor is a temperature- based sensor. This sensor consists of multiple temperature sensors that read the temperature at different levels. Based on the temperature at each location, it can be determined if the pump must to be shut off. The last sensor is a magnetic reed switch and float sensor. This sensor consists of a floating magnet on an track that triggers the magnetic reed switch to shut off the pump. The data from the three sensors are interpreted by a digital signal controller to improve the accuracy of the system. The purpose of having three sensors is for intermittent error correction to ensure the pump runs as much as needed Without allowing pump failure. Introduction: Norfolk Southern Corporation has implemented the Wayside Top of Rail systems that dispense lubricant onto train tracks to reduce friction. The lubricant inside the tank must not sink below the pump intake level. This situation causes air to enter the pumps leading to malfunction. The locations where these systems are installed have a refilling schedule that is hard to implement due to varying track use and track location. Craig ZofchakManager Michael DowWebmaster Nicholas VogtmannDocument Prep George BalliosLab Coordinator Final Product/Project Results: When collecting data from our final product we have concluded that the magnet float sensor is the most accurate, but it is required to have some internal components. The audio frequency sensor does have a variance when the water level reaches the critical, but it has room for improvements based on the frequency dose not vary enough. The temperature sensor has a good theory to back it up, but the fact that it requires a lot of time to computer the different level leaves room for improvement. The fact that each one has a minor flaw is why we decide to implement them all together to make a more robust system. Prof. Virginia AyresFacilitator Kevin ConnSponsor