Jiangsu Key Laboratory of Intelligent Agricultural Equipment

Nanjing, China

Jiangsu Key Laboratory of Intelligent Agricultural Equipment

Nanjing, China
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Ren S.,Nanjing Agricultural University | Zou X.,Jiangsu Key Laboratory of Intelligent Agricultural Equipment | Su J.,China Aerospace Science and Technology Corporation
Boletin Tecnico/Technical Bulletin | Year: 2017

This paper studies the completeness of Robust and Complete Agricultural Control (abbreviated as RCAC) having skewed temporal control object with uncertain logic. The weighting algorithm based on the output error index of the model is used to replace the traditional weighting algorithm based on the Bohr filter and Heinstein posterior probability formula. Under the premise of weight convergence, the theory which is based on independent normal system (abbreviated as INS) gives the completeness evidence of the such kind of robust complete agricultural control system, and generalize the results to a class of nonlinear slow time-varying control objects that can be approximated by multiple linear system models. Experiments show that the system has good completeness and robust ability. It can achieve high control accuracy.


Lu Z.,Nanjing Agricultural University | Lu Z.,Jiangsu Key Laboratory of Intelligent Agricultural Equipment | Guo B.,Nanjing Agricultural University | Guo B.,Jiangsu Key Laboratory of Intelligent Agricultural Equipment | And 2 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2013

There are many ways to control depth of tractor's electro-hydraulic lift hitch at home, however, force control or position control takes the main place and force-position combined control was studied less. The force-position combined control based on fuzzy control was brought forward in this article, and it can achieve the goal of depth's multi parameters control. Firstly, the structure of tractor's electro-hydraulic lift hitch and principle of the system are introduced. Then, the introduction of force-position combined control based on fuzzy control was proposed, the comprehensive coefficient was defined as the proportion of position control in force-position combined control. Actual value was calculated in advantage of depth value and resistance. The actual value was compared with the target value and then fuzzy control algorithm works. The essence of this control was that system transforms force-position combined control to depth fuzzy control in use of comprehensive coefficient. Besides, the depth fuzzy controller was designed. At last, the effect of resistance on depth in different comprehensive coefficient was studied through experiments. The results showed that the response of depth from 0 to 20 cm was less than 1.7 s. When comprehensive coefficients were 0.7, 0.5, 0.3, the depth's decrease showed as 3.2, 3.8 and 5.6 cm respectively. Meanwhile, the adjusting time showed as 0.79, 0.93 and 1.21 s respectively. It met the requirement of quick response of hydraulic lift hitch. When the comprehensive coefficient gets bigger, the effect of resistance to depth is less conversely. When the comprehensive coefficient is not zero, the system can keep depth and engine load stable at the same time. Driver can set the value of comprehensive coefficient to make electro-hydraulic lift hitch system adjust to many kinds of soils. Compared with the force control or position control, force-position combined control has more advantages. In the article, force-position combined control based on fuzzy control was presented and studied. The results reflect the dynamic characteristics of the electronically controlled hydraulic hitch system for ploughing depths control; and provide a theoretical basis for the controller design of the tractor's electro-hydraulic lift hitch system according to force-position combined control.

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