# Multibody Dynamics Simulation and Vibration Test for High Clearance Orchard Sprayer
## 1 Introduction  
Due to the fact that large-scale high clearance sprayers can solve the problem of difficult drug delivery and poor control effect of high stalk crops in the middle and late growth period [1; 2; 3]. As a high-efficiency plant protection operation machine, the high clearance sprayer is favored by relevant plant protection operators because of its fast operation speed, high pest control efficiency, and not ease to damage crops [4; 5; 6]. As the high clearance sprayer chassis frame carries heavy equipment such as water tanks (full load) and engines, the load impact when subjected to road excitation has a significant impact on the sprayer chassis frame [7; 8]. A safety analysis of the sprayer chassis frame is essential [9; 10]. The high clearance sprayer provides a multifunctional application platform for plant protection operations, meeting the application requirements of different sizes of plots and the standard of uniform application [11; 12]. Based on the Newmark-\(\beta\) method, [PERSON] et al. proposed a numerical simulation method for solving the differential equations to study the effect of the man-machine seat of a high clearance sprayer machine under load excitation [13]. A finite element model of the high clearance sprayer was established, [PERSON] et al. analyzed and tested that the overall strength and stiffness of the chassis frame of the high clearance sprayer met the requirements [14]. The spray boom system of sprayers is increasingly being investigated, as the effects of ground excitation on sprayers can be evident in the vibration behavior of the sprayboom [15; 16]. [PERSON] et al. established a system of higher-order differential equations to describe the kinematic behavior of the spray bar using kinetic equations, the dynamic characteristics of the passive suspension are investigated, and the effects of factors such as damping, friction, and pendulum length on the response characteristics are analyzed [17]. [PERSON] et al. use ultrasonic sensors to measure the height difference between the two ends of the spray bar and use the measurements to calculate the required spray bar tilt angle for control, using the control system to keep the bar in the desired position [18]. The optimization and improvement of various vehicle components through digital prototype analysis have been widely used. A finite element model of the frame of an agricultural vehicle was carried out in virtual model simulation, [PERSON], and provided a basis for subsequent optimization of the frame structure based on the simulation results [19]. A finite element model of the tipper frame was established and carried out simulation analysis of its static and dynamic performance by [PERSON], obtain the variation of the amplitude and deflection of the tipper frame and the stress distribution state of the frame, provide a reference for the subsequent improvement of the frame [20]. With innovations in measurement methods, there are various ways of testing the properties of metallic materials. Digital image correlation system (DIC) combined with related technology can be used to observe the stress concentration area of metal materials and predict the location of the failure area [21; 22]. The use of 3D laser Doppler vibration measurement systems for non-contact inspection of materials is an advanced technological tool. The technique allows measurements to be made without touching the object and can be used for modal analysis of objects and surface quality inspection [23; 24]. For large frame vibration tests, triaxial acceleration sensors are now mostly used. The amplitude and frequency of the frame vibrations are measured in the vibration test to assess the safety of the vehicle [25]. As a highly efficient plant protection machine, the large cross-row sprayer is often used for spraying high stalk crops. High clearance sprayers designed for use in grape orchards to improve the efficiency of orchard operations.