Research On Dynamic Performance Of The Tracked Orchard Platform

The demand for tracked orchard platform is becoming more and more significant with the orchard scale developing and the requirements of the standardized management in our country. At present, the study of performance with traditional development mode needs physical test for many times. Thus the cost is higher and the development cycle is longer. However, the overall unit performance can be predicted before putted into manufacture if virtual prototype technology and multi-body dynamic simulation are used. Then the times of physical test will be decreased and test security will be improved. It also reflects the actual driving conditions of the machine more truly than conventional statics method. The technology provides the basis for the design of the tracked orchard work platform. At the same time, manufacturing cost of the physical prototype will be reduced during the product development and the development cycle will be cut down. The method is advanced and reliable. Based on the tracked orchard work platform as the research object, the three-dimensional model of the platform was assembled by CAD technology and the simulation of dynamic performance was completed by VPT. The specific research contents and conclusions are as follows:(1) The parts of the tracked orchard platform were established by the three-dimensional design software SolidWorks. Then the virtual assembly machine was complete based on the overall arrangement type. After analyzing the gravity center of the machine and the interference, the results show that the position of gravity center is reasonable and there is no interference among any parts. Besides, the motion simulation of lifting platform was completed. And the results show that the structure of lifting platform is reasonable and the motion is correct; the maximum lifting height is 618 mm and the maximum area of platform is 1304795mm2.(2) Base on the general assembly model, the dynamic simulation model of the tracked orchard platform was built with the multi-body dynamics software RecurDyn. Then the simulation test and analysis were conducted on the model. The results show that the vibration of the tracked orchard platform is slight while becomes stable gradually, and the model is reliable and effective.(3) Driving and steering dynamics of crawler orchard work platform were analyzed from the theory aspect. Then the straight process test was simulated under the working condition of straight line driving. The results show that driving torque and ground pressure curve are regular; the sinkage depth is 35 mm on the horizontal ground; the distribution of ground pressure is further from the roller, the slighter pressure; and the tracked orchard platform is driving stably during the process of straight line driving. Following, the steering process test was simulated under the working condition of steering. The results show that the speed is higher, the stability is worse; the resistance of differential steering is lower than pivot steering, and its stability is better, but the steering radius is bigger and the steering speed is slower; the steering resistance of outside track is larger than inside during the process of steering.