Multi-objective optimization of cross-section integrity rate and sawing power consumption in sawing Caragana korshinskii Kom. branches

Abstract

Caragana korshinskii Kom. (CKK) is one of the main trees for wind and sand control in northwest China. According to its biological characteristics, flat stubble is the main measure and the critical stage of nurturing management. However, the quality of the CKK sawing surface not only affects the sprouting rate of the following year but also reflects the mechanical properties of flat stubble. To reduce the sawing power consumption of the CKK stubble device and improve the quality of sawing cross-section, this paper conducted branch sawing tests on a self-designed sawing experiment rig. Using the central composite design test method, the operating parameters of the sawing experiment rig were studied experimentally, with sawing speed (va), moving speed (v’f), and inclination angle of the circular blade (α) as the influencing factors, sawing power consumption (Y1) and cross-section integrity rate (Y2) as the objective functions, to establish a multiple mathematical regression model between them. The test results show that the influence of each factor on the sawing power consumption in the order of significance is the va, v’f, and α, and the influence of each factor on the cross-section integrity rate in the order of significance is the v’f, va, and α. The optimal combination of working parameters is va of 42 m/s, v’f of 0.3 m/s, and α of 10°, which corresponds to Y1 and Y2 of 279.73 W and 82.6% respectively. Based on the optimal combination of working parameters, the prototype was processed and field tests were conducted. The field test results showed that the stubble breaking rate and missed cutting rate of the CKK harvester are 5.5% and 4.7% respectively, and the CKK branches sprouted well in the following year after flattening the stubble, which all met the requirements of the CKK harvesting operation.