Biological Systems Engineering


First Advisor

Santosh Pitla

Second Advisor

Carl Nelson

Date of this Version



Liew, C. (2021). Development of Tractor Instrumentation System: Hydraulics, And Controller Area Network (CAN) Data Analysis of Agricultural Machinery (Master's thesis). University of Nebraska-Lincoln, Lincoln, NE.


A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Majors: Agricultural and Biological Systems Engineering and Mechanical Engineering and Applied Mechanics, Under the Supervision of Professors Santosh K. Pitla and Carl Nelson. Lincoln, Nebraska: August 2021

Copyright © 2021 Chee Town Liew


The tractor is a very important piece of machinery in agriculture, and it has been evolving and progressing over the years with improved and increasingly complex functionality. Controller Area Network (CAN) has been incorporated into tractors and other machinery with SAE J1939 and ISO 11783 standards, serving as the communication bus for various on-board electronic controller units (ECUs), and carries various machine operation data that can be used for analyzing machine performance. Investigation of data extraction from CAN messages was conducted by examining the SAE J1939 and ISO 11783 standards. A case study on CAN bus data analysis for a combine harvest operation was done to demonstrate the capability of CAN reported data. A Gaussian Mixture Model (GMM) was used for unsupervised learning analysis of the machine load states, and three machine load states were proposed, namely, idle, transport and working states, to characterize machine in-field load states. Sensor CAN Gateway (SCANGate) was developed for logging data from external sensor instrumentation. SCANGate collected and merged sensor data with CAN Bus and allowed synchronization of CAN reported data and sensor data. Several upgrades to the original SCANGate were done to improve its functionality and durability. A tractor hydraulic instrumentation system was also developed in this study to investigate the in-field tractor hydraulic power usage. Custom orifices were designed and fabricated as a cost-effective solution for hydraulic flow measurement instrumentation. In combination with pressure gauges, hydraulic power usage was computed. Planting operation data collection was used to validate the hydraulic instrumentation system.

Advisors: Santosh K. Pitla & Carl Nelson