# Design and Testing of a New Bionic Corn-Ear-Picking Test Device
## 1 Introduction  
In recent years, with the change in people's dietary structure, there is a demand for food that is not only delicious, but also health conscious. Fresh corn has gained popularity because of its high nutritional value [1; 2]. At the same time, it has earned a reputation as being \"value added\" because of its higher economic value compared to regular corn [3; 4; 5]. In order to ensure the taste, fresh corn must be picked within a very short harvest period [6]. However, due to its high moisture content, the existing machinery in the harvesting process very easily causes damage to the cob, and this affect the taste and even causes mildew [7; 8; 9; 10]. As a result, a large part of the corn is still picked manually, limiting the planting scale. Therefore, there is an urgent need for a harvesting machine suitable for fresh corn cob picking to be applied in mechanical operations [11; 12].  
At present, the harvesting operation of fresh corn is still dominated by the application of common corn harvesters [13]. The core components for the purpose of picking ears are mostly based on two working principles, one of which is to use two relatively rotating picking rollers to restrict the passage of the corn cob through the rubbing and squeezing of the stalk and cob to achieve the picking of ears [14], as shown in Figure 0(a). The amount of power consumption of the cob picking device using this principle is high, and the problem of cob gnawing is more serious, especially for fresh corn, where the kernels become pulpy inside and breakage directly reduces the quality of the corn [15]. Another type is the combination of the picking plate and stalk pulling roller, which involves using the stalk pulling roller to block the corn cob and achieve corn picking by stretching and squeezing the stalk, as shown in Figure 0(b). Although the damage to the corn cob rubbing is reduced, due to the high water content and toughness of the stalks and outer bracts of fresh corn and the non-adjustable gap between the stalk pulling roller and the picking plate duringharvesting, it is very easy for it to cause blockages and affect the efficiency rate [16]. In summary, two ways of picking corn ears can be achieved by applying a forceful stretching action between the corn ears and stalks that exceeds the connection force between them [17], both of which are relatively energy consuming. Both of them are not suitable for fresh corn picking operations because of the limitations of their operating principles.  
In order to solve the above problems and find a suitable method for fresh corn picking, a method of picking corn that imitates the manual breaking of corn is proposed. In addition to being applicable to the physical characteristics of fresh corn and reducing the amount of picking damage, this method can significantly reduce the energy consumption during the picking process, and it can preserve the intact corn stalks for full-scale corn harvesting. In addition, to verify the feasibility of the proposed method, mechanical experiments were conducted to compare with the tensile picking principle used by most current harvesters to prove the rationality of the proposed method. Moreover, a fresh corn picking test stand was designed based on this principle, and the optimal operating parameters of the test stand were obtained by orthogonal and Box-Behnken tests.