A Navigation Control Method for Farm Tractor Based on Nonsmooth Control and Disturbance Observation

Abstract

The invention discloses a navigation control method on the basis of non-smooth control and disturbance observation for an agricultural tractor. The navigation control method is characterized in that a kinetic model is converted into a semi-linear model containing a linear portion and a nonlinear portion, the linear portion brings convenience for a control design, and the control precision is affected by the nonlinear portion; state feedback of the linear portion is designed by a non-smooth technology, and a disturbance observation design is performed on the nonlinear portion; the state feedback on the basis of the non-smooth technology is combined with feed-forward of the disturbance observation, so that a linear navigation compound control scheme for the agricultural tractor can be obtained. The navigation control method has the advantages that the nonlinear portion of a system is observed and compensated by the aid of a disturbance observer, so that the influence of the nonlinear portion on the control design of the linear portion is reduced; parameters of a non-smooth controller of the system are regulated according to regulation rules for parameters of a non-smooth system, so that the influence of the nonlinear portion of the system and external disturbance can be further eliminated, and the linear navigation quick performance and the linear navigation disturbance resistance of the agricultural tractor are improved.

Description

technical field [0001] The invention relates to a navigation control technology of an agricultural tractor, specifically uses a non-smooth control method and a disturbance observation technology to improve the navigation speed and precision of the agricultural tractor, and belongs to the technical field of precision agriculture. Background technique [0002] In recent years, precision agriculture has become an important branch of agricultural information technology applications. The application of precision agricultural technology can greatly improve the accuracy of operations, reduce repetitive operations, save energy, protect the environment, and maintain the sustainable development of agricultural production. Agricultural tractor is the main platform to realize various agricultural mechanization operations, the most important power machinery in agricultural production, and an indispensable material carrier for the implementation of precision agriculture. With the improve...

AI Technical Summary

Problems solved by technology

First, the operational skill level of the agricultural tractor driver affects the operation accuracy

For example, when the driver walks along a straight path for a long time, it will inevitably bring greater labor intensity to the driver and affect the operation accuracy.

Second, the working method of the tractor itself affects the operation accuracy

However, in the complex environment of farmland, when the agricultural tractor is close to the target line, the speed is slow, and its steady-state performance is often not satisfactory

The main reason is that when the state of the navigation system is close to the target line, the state variable is small, so the control energy is also small. Due to the external factors that affect the navigation accuracy, such as the height of the field, the resistance of the crops, etc., they do not decrease with the decrease of the state. disappear, so the convergence speed and navigation accuracy of the system cannot meet the requirements

[0005] In short, the existing PID-based control method can satisfy the dynamic performance of linear navigation of agricultural tractors, but it is difficult to meet the steady-state performance of high-precision navigation, which is manifested in the low navigation accuracy, that is, the large error from the expected trajectory, Therefore, it is difficult to meet the navigation requirements of agricultural tractors in actual operations

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