Load torque estimation for a parallel hybrid agricultural tractor in field operations

• Published in: International journal of precision engineering and manufacturing Vol. 14; no. 10; pp. 1865 - 1868
• Main Authors: Kim, Yong Joo, Song, Bongsob, Kim, Jinho
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2013
• Subjects: Engineering; Industrial and Production Engineering; Materials Science; Torque estimation; Hybrid tractor; Torque-assist strategy; Adaptive observer
• ISSN: 2234-7593; 2005-4602
• DOI: 10.1007/s12541-013-0250-4

This paper presents a load torque estimation algorithm for a parallel hybrid agricultural tractor (HAT) in major field operations such as baling, plowing, and rotary tillage. While the load torque in a hybrid electric vehicle is mostly used to make the vehicle drivable, a large portion of the load torque in a HAT is required for field operations. To identify dynamic characteristics of each field operation, both PTO and transmission torque in major field operations are measured. Based on the measurement results, it is inferred that the load torque estimation is necessary to develop a torque-assist strategy to capture the characteristics of the field operation. Thus, an adaptive observer is proposed for the load torque estimation, and its performance is validated experimentally by comparing the estimated load torque with the measurements.