ENGINEERING

Development and performance evaluation of lateral control simulation-based multi-body dynamics model for autonomous agricultural tracto

Mo A Son1, Hyeon Ho Jeon2, Seung Yun Baek2, Seung Min Baek2, Wan Soo Kim3, Yeon Soo Kim4, Dae Yun Shin5, Ryu Gap Lim6,*, Yong Joo Kim1,2,7,*

1Department of Agricultural Machinery Engineering, Chungnam National University, Daejeon 34134, Korea
2Department of Smart Agriculture System, Chungnam National University, Daejeon 34134, Korea
3Department of Bio Industrial Machinery Engineering, Kyungpook National University, Daegu 41566, Korea
4Department of Bio Industrial Machinery Engineering, Pusan National University, Miryang 50463, Korea
5Chungnam National University, CEO, Sejong Rain Co., Ltd., Daejeon 34134, Korea
6Innovalley Substantiation Team, Korea Agriculture Technology Promotion Agency, Iksan 54667, Korea
7Department of Biosystem Machinery Engineering, Chungnam National University, Daejeon 34134, Korea

*Corresponding authors: limso@koat.or.kr, babina@cnu.ac.kr

Abstract

In this study, we developed a dynamic model and steering controller model for an autonomous tractor and evaluated their performance. The traction force was measured using a 6-component load cell, and the rotational speed of the wheels was monitored using proximity sensors installed on the axles. Torque sensors were employed to measure the axle torque. The PI (proportional integral) controller’s coefficients were determined using the trialerror method. The coefficient of the P varied in the range of 0.1 – 0.5 and the I coefficient was determined in 3 increments of 0.01, 0.05, and 0.1. To validate the simulation model, we conducted RMS (root mean square) comparisons between the measured data of axle torque and the simulation results. The performance of the steering controller model was evaluated by analyzing the damping ratio calculated with the first and second overshoots. The average front and rear axle torque ranged from 3.29 – 3.44 and 6.98 – 7.41 kNm, respectively. The average rotational speed of the wheel ranged from 29.21 – 30.55 rpm at the front, and from 21.46 – 21.63 rpm at the rear. The steering controller model exhibited the most stable control performance when the coefficients of P and I were set at 0.5 and 0.01, respectively. The RMS analysis of the axle torque results indicated that the left and right wheel errors were approximately 1.52% and 2.61% (at front) and 7.45% and 7.28% (at rear), respectively.

Keywords

agricultural tractor, lateral control, multi body dynamics model, performance evaluation, simulation

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