**Preface**

Harvesting is one of the most important aspects of agricultural production. The development of harvesting tools has a long history: as early as the Stone Age, people used stone sickles and other tools to harvest grain. In the late 19th century, agricultural mechanization began to emerge, and people began to try to use mechanized equipment to replace the traditional human labor. In 1799, the earliest horse-drawn disc cutter harvester appeared in the United Kingdom; 1822 saw the cutter on top of the additional paddle device. In 1826 marked the emergence of the use of a reciprocating cutter and paddle wheel of the prototype of the modern harvester, with horse traction and through the rotation of the ground wheel drive cutter. Around 1831∼1835, similar animal-powered wheat harvester in the United States were commercialized; in 1851 saw the emergence of machines to cut down stalks into a pile with a rocking-arm harvester as well as the application of internal combustion engines to make the harvester more efficient and flexible. Years later, in 1920, due to the widespread use of tractors, the tractor with a harvester began to replace the animal-powered harvester. The types of harvests also expanded gradually from the earliest grains to a wide range of crops such as fruits, vegetables, and cotton. In the 21st century, with the continuous progress of science and technology, the degree of automation of the harvester is higher and higher. Especially in recent years, visual perception technology, satellite navigation technology and intelligent decision-making algorithms have been applied on a large scale on the harvester, which has enabled the harvesting machine intelligence to rapidly improve and gradually transition to unmanned operation.

The focus of harvester research efforts now includes mechanical components and intelligent systems, including the development and optimization of harvesting components for specific crops and the design and optimization of travel components for different terrain and soil conditions. Intelligent system research includes operating environment sensing and crop target recognition, decision-making and control of operation and traveling. It is graphically summarized as the following key technologies: precise identification and positioning systems ("eyes"), sensitive decision-making and control systems ("brain"), highly adaptable chassis and mobile platforms ("feet"), efficient end-effectors and harvesting components ("hands"), etc. In order to gather excellent papers in this field and showcase the latest ideas, we have organized a Special Issue of Agriculture entitled "'Eyes', 'Brain', 'Feet' and 'Hands' of Efficient Harvesting Machinery", and a total of 21 research papers were selected for inclusion in the Special Issue. These papers address harvesting components, traveling mechanisms, sensing systems, and decision-making algorithms for a wide range of crop harvesters, including grains, vegetables, and fruits, and provide key technical references for efficient harvesting machinery research.

> **Cheng Shen, Zhong Tang, and Maohua Xiao** *Editors*
