## 1 Introduction  
Soil compaction is one of the most severe forms of soil degradation caused by traditional tillage practices, and it refers to the decrease in porosity between soil aggregates [1, 2, 3]. The damage of soil compaction on cultivated land, specifically in the form of stunted crop root growth, affects crop growth [4]; the supply chain of water and nutrients in the soil will be broken [5], with the microbial colony imbalance; the number of host organisms, such as earthworms, will decrease [6]. These damages ultimately affect crop production and cause severe economic losses to the world [7]. Crop production loss due to soil compaction was as much as $1 billion per year in the United States and $144 million per year in just one agricultural region of Australia [8, 9]. Currently, subsoiling operation is one of the most effective methods to solve the soil compaction problem [10, 11, 12]. Subsoiling can break the plow plough pan, improve the soil water storage and moisture conservation capacity, and significantly improve crop production [13]. However, due to the large depth of subsoiling operation, the subsoiling resistance is also significant, and it is very easy to form big soil nuclear at the subsoiler shovel tip [14]. This not only leads to increased subsoiling resistance, increased energy consumption, and poor subsoiling operation quality but also is easy to cause damage to machines and tools in severe conditions [15]. This problem can be solved by bionics, electro-osmosis, and vibration methods [16; 17; 18]. The bionic and electro-osmosis approaches are highly dependent on the parameters such as soil type, moisture content, and soil firmness, although they can achieve resistance reduction [19; 20]. Numerous studies have shown that the vibration resistance reduction effect of the soil-touching component was highly adaptable in different soil environments [21; 22; 23]. The vibration subsoiling mechanism can be divided into two types, which are forced vibration and self-excited vibration according to the different vibration sources [24]. A forced vibration subsoiling mechanism needs an additional vibration exciter, generally uses the output shaft of the tractor as the energy source, and transmits the output power to the vibration exciter so that the subsoiler can vibrate with a specific frequency and amplitude. The subsoiler under this type of vibration is rigidly connected with the vibration exciter. Although it can reduce the resistance, it is limited by the mechanical structure, and the frequency is generally low. Moreover, the total energy consumption of subsoiling operations will increase due to the need for the tractor output power as a vibration source [25]. The self-excited vibration subsoiling mechanisms use the resistance in the subsoiling process to excite the vibration of elastic elements on the subsoiling machine to realize the vibration function. Many self-excited vibration subsoiling machines use springs as elastic elements, which do not need to consume extra energy. However, since the excitation of vibration depends on the subsoiling resistance, there are many uncertain factors for the changes of resistance in actual operations; its vibration frequency and amplitude are uncontrollable. Moreover, due to the elasticity of the vibration mechanism, the penetration angle of the subsoiler tip will change during the vibration process, which will increase the subsoiling resistance [26]. As animals in nature have evolved over billions of years, they have exhibited high adaptability to their environment. The challenge of drag reduction in subsoiling was solved by the bionic approach in this study. The antilon larvae, which are good at digging, were taken as the bionic prototype; its vibration excavation characteristics and non-smooth surfaces structure characteristics were applied to the design of the subsoilers. Antlions belong to the Myrmleontidae, Neuroptera. Additionally, its larvae are one of the few soil animals that are good at drilling holes in the soil by vibration [27; 28; 29].