# Design and Testing of an Intelligent Control System for Maize Picking Harvest
## 1 Introduction  
The working parameters of a maize harvester are coupled, and they mutually influence each other. With the development of large-scale and intelligent maize harvesters, it has become increasingly difficult for operators to observe harvest losses, determine the causes of such losses, and adjust the working parameters relying solely on their hearing and vision. This also affects the operating efficiency and harvest quality of the maize harvesters [1, 2]. In China, the present grain harvest rate only accounts for 5-6% of the maize planting area, and maize remains mostly harvested by ear [3]. However, this approach has some problems, such as unsuitable agricultural machinery and agronomy, and the planting mode is not unified. This has led to ear loss and poor stability and adaptability of maize harvesters. According to statistics, maize picking loss rate is 75.28% of the total loss rate and is the main component of losses [4, 5]. The maize picking mechanism is the core component of a maize harvester, and its performance directly affects the loss and damage of ears [6, 7, 8]. Thus, an intelligent control system for the maize picking process should be designed to ensure the maize harvest quality. In combine harvesters, automatic control has been applied for the header height and operating speed to reduce harvest losses, operator fatigue, and the risk of equipment damage. A sensitivity based integrated robust optimal design (IROD) methodology is used to determine optimal structural parameters concurrently with a controller to improve header height control performance for a combine harvester. The problem is to control the height at a constant distance above the rough terrain during harvesting [9]. [PERSON] designed a linear quadratic regulator(LQR) controller and a two degrees of freedom(DOF) controller for combine harvester header height control [10; 11]. Domestic scholars have also attempted to develop automatic control systems for the header height on the basis of height detection sensors [12; 13]. Although the above studies used simulations for their analysis, field tests were not completed. Fuzzy adaptive control have been applied to the operating speed control to manage the nonlinearity and complexity of the combine control system [14]. In addition, [PERSON], [PERSON] et al. established an automatic control model combined with a fuzzy proportional-integral-derivative (PID) control algorithm for the rotational speed of a reel, which they verified through field tests [13; 15]. Although several studies have considered the automatic control of combine harvesters, few studies have focused on automatic control of the rotational speed of pulling rollers. Furthermore, the above research was focused on adjusting a single working part, and the individual working parameters were considered independently. For the combined regulation and control of several factors, most research has focused on the threshing and cleaning parts of the maize combine harvester. When combined with expert knowledge, a fuzzy controller can automatically adjust the threshing cylinder speed, sieve clearance, fan speed, and operating speed to minimize the grain loss [16]. Additionally, the fuzzy control method and power consumption model of the threshing cylinder can be used to design a controller to match the threshing cylinder speed and operating speed [17]. Scholars at home and abroad have introduced intelligent control technologies such as fuzzy control, PID control, adaptive control, neural network control, and composite intelligent control to combine harvesters to realize the real-time adjustment of the working parameters under different conditions and reduce the harvest loss. At present, real-time adjustment of the rotational speed of pulling rollers, as well as joint control of multiple factors affecting maize picking, has not been realized. This has led to problems with the maize picking process, including broken ears, ears and kernels falling, and several broken stems.