Design and experiment of small lifting platform in orchard

Abstract: Lifting platform in orchard is of great importance to the fruit production, because it plays a vital role in the operation links: picking, flower thinning, etc. However, current mechanical devices are not suitable for orchard in the southern hillside area due to the complex terrain. It means low efficiency and the need for more farmers. Mechanization is the only way to change the present situation. Therefore, based on studying and analyzing the collected data of orchard in south China, a miniature self-propelled lifting platform was developed to increase the operation efficiency in orchard in the southern area. The lifting platform was mainly composed of the crawler, scissors elevating mechanism and a multi-function manned worktable. In particular, the manned worktable was designed to realize the real-time leveling through the means of azimuth adjustment, lifting and angle adjustment which were separately driven by revolving support and hydraulic cylinders. In order to maintain stability of the worktable and increase worker's comfort, the secondary leveling was crucial. In order to make the platform has the advantages of small external size, compact structure and easy to assemble, the dimensions of the mechanism and main technical parameters of key parts were optimized based on preliminary experiments. The prototype was made in a machine processing factory and driven directly by a 4.41 kW diesel engine. With the aim to evaluate the performance of the platform, tests of the prototype including climbing angle test, turning radius test, leveling performance test, and stable performance test were carried out in the simulated work environment. The experimental results indicated that the running speed of the prototype was 0.12-0.25 m/s, and the maximum lifting height was 1.2 m, and the turning radius was 0.75-1.34 m, which meet the design requirements and are suitable for the varied working environments. In addition, the simulation results revealed that the static tipping angle of the prototype was between 15°-30° when the platform was equipped with different loads and in various lifting height. Moreover, the mechanism can adjust the inclination angle of the manned worktable through the secondary leveling, which demonstrated that this mechanical platform can be used to work in difficult terrain. But because the distribution of weight is uneven and the chassis touches the ground in a small area, the stability of the whole machine is decreased. All the experiments concluded that the lifting platform met the needs of fruit production and fruit transportation. Meanwhile, with smaller outline size, it is easy to operate and suitable for orchard planting pattern and use requirements in the South. The study provides guidance for the practical production.