**5. Conclusions**

In order to quickly dry peanut pods and effectively reduce the mildew of peanut pods sticking to the ground in rainy weather, this paper analyzed the current research status of peanut digging and inverting technology in China and abroad. Combined with the two-stage harvesting mode of peanut, the orthogonal experiment was carried out with the peanut digger-inverter on the upright peanut under two states of pressed and unpressed vines. The results showed that:

(1) Through the analysis of range, variance, and the comprehensive balance method of an orthogonal experiment, it can be seen that the influence sequence of each factor of the peanut digger-inverter on the evaluation index under the condition of unpressed vines is as follows: A > C > B, the best horizontal combination is A2C3B2, that is, the speed of the tractor is 0.9~1.1 m/s, the line speed of the conveying chain is 1.02 m/s, and the line speed of the inverting roller is 2.12 m/s. Under the horizontal combination, the experimental results were as follows: the average travelling speed of the tractor was 1.06 m/s, the rate of vines inverting was 71.07%, the rate of buried pods was 0.2%, and the rate of fallen pods was 0.22%.

(2) Through the analysis of range, variance, and the comprehensive balance method of an orthogonal experiment, it can be seen that the influence sequence of each factor of the peanut digger-inverter on the evaluation index under the condition of pressed vines is as follows: A > C > B, the best horizontal combination is A2C2B2, that is, the traveling speed of the tractor is 0.9~1.1 m/s, the speed of the conveying chain is 1.02 m/s, and the line speed of the inverting roller is 1.88 m/s. Under this horizontal combination, the experimental results were as follows: the average travelling speed of the tractor was 1.01 m/s, the rate of vines inverting was 74.29%, the rate of buried pods was 0.14%, and the rate of fallen pods was 0.33%.

(3) Through the paired *t*-test, it can be seen that under the state of pressed vines and unpressed vines, there is little difference in the influence of various factors on the rate of fallen pods and the rate of buried pods, but there is a difference in the influence on the rate of vines inverting. The rate of peanut vines inverting under the state of pressed vines is higher than that under the state of unpressed vines.

On the basis of the optimization of the working parameters of the peanut diggerinverter, in the future, we will develop a set of the peanut digger-inverter suitable for upright peanuts and carry out intelligence and information research on the existing basis.

**Author Contributions:** Conceptualization, H.S., F.G. and Z.H.; methodology, H.S. and H.Y.; software, H.S. and H.Y.; validation, H.S., H.Y. and F.W.; formal analysis, H.S. and Q.G.; investigation, Q.G.; resources, F.W.; data curation, H.S., F.W. and Y.C.; writing—original draft preparation, H.S.; writing—review and editing, M.C., Q.G. and Z.H.; visualization, Y.C.; supervision, Z.H.; project administration, M.C.; funding acquisition, F.G. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the National Peanut Industry Technology System, grant number CARS-13.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on demand from the first author at (82101221060@caas.cn).

**Acknowledgments:** Thanks to Ganzhou Experimental Station of the National Peanut Industry System for providing the experimental site.

**Conflicts of Interest:** The authors declare no conflict of interest.
