*Article* **Experimental Analysis and Verification of the Influence on the Elastic Recovery Coefficient of Wheat**

**Jizhong Wang, Weipeng Zhang, Fengzhu Wang, Yangchun Liu, Bo Zhao and Xianfa Fang \***

National Key Laboratory of Agricultural Equipment Technology, China Academy of Agricultural Mechanization Science Group Co., Ltd., Beijing 100083, China

**\*** Correspondence: fangboshi2023@163.com

**Abstract:** To establish a collision model of wheat grains impacting a force plate with a piezoelectric sensor, and to investigate the influence of the elastic recovery coefficient on the sensor's detection accuracy during the collision process, this study employed object kinematic principles to construct a wheat elastic recovery coefficient measurement device. This device ascertains the elastic properties of wheat during collisions and determines the elastic recovery coefficient of the wheat collision model. The wheat variety Jinan No. 17 was selected for testing, and the effects of the contact material, grain drop height, material thickness, and grain moisture content on the collision recovery coefficient during the collision process were analyzed through single-factor and multi-factor experiments. The experimental results demonstrate that the collision recovery coefficient of wheat grains increases with the stiffness of the collision materials for different materials. The grain recovery coefficient of wheat exhibits a downward trend with increasing falling height and moisture content, while it tends to rise as the material thickness increases. Data analysis and comparison reveal that, given the determination of the collision material, the moisture content of wheat exerts the most significant effect on the elastic recovery coefficient, followed by material thickness, while the influence of falling height is less pronounced. The findings of this study can provide data support for simulation testing and product design of wheat combine harvester cleaning screen body mechanisms and wheat seeders.

**Keywords:** response surface method; collision model; elastic recovery coefficient; elastic characteristics; kinematics
